Protecting the skin against UV radiation is an important measure to prevent skin cancer, and preventing excessive exposure of infants and children’s skin to UV radiation is of special significance. It is well known that due to the high outdoor activities of children and adolescents, the accumulation of UV radiation before the age of 19 accounts for half of the lifetime accumulation. Moreover, studies have also found that sun spots in childhood have important implications in the pathogenesis of malignant melanoma. Therefore, sun protection for infants and children is of great importance for skin health. The thickness of the skin varies from person to person and from site to site. The skin on the bottom of our feet is the thickest and the roughest to touch; the skin on the face is thinner and more tender to touch, while the baby’s skin is the most lovable, soft and smooth, and especially comfortable to touch. This special comfort is because the skin of infants and children is much thinner than that of adults, mainly because the stratum corneum is much thinner. The stratum corneum is the first barrier to skin sun protection, reflecting and absorbing ultraviolet rays, the thinner the stratum corneum, the more ultraviolet rays into the deeper layers of the skin, the more serious the damage caused; in addition, babies often play outdoors, receiving longer exposure to ultraviolet rays than adults, the damage of ultraviolet rays have a cumulative effect, the longer the time, the more serious the damage to the skin, so the baby’s sun protection is more important than adults. Our parents know that babies need more sunlight so that they can promote calcium absorption. Therefore, once the sun is shining, mothers often let their babies stay in the sun for a long time, which is not appropriate. Some studies have confirmed that only 15 minutes of UV exposure per day is needed to complete the daily synthesis of the required vitamin D. Therefore, young mothers do not need to worry about their baby’s calcium deficiency because of less sunlight. There are also many mothers who believe that babies do not need to use sunscreens because the physical or chemical components in these sunscreens can damage the baby’s skin. In fact, this view is also incorrect. Because the baby’s skin barrier function is not sound, we need to use some sunscreens to help baby’s skin resist UV rays, maintain skin health and resist adverse external stimuli. If we don’t protect our babies from the sun, will it cause serious consequences? Acute damage to the skin from UV rays mainly includes sunburn or photosensitive diseases. If the baby itself suffers from light diseases, such as lupus erythematosus, niacin deficiency, seed pox-like blister disease, etc., sun exposure will induce or aggravate the disease; if in taking certain drugs such as sulfa drugs, certain foods such as mud snail, gray vegetables, etc., sun exposure will induce photosensitive diseases. The chronic damage of ultraviolet light is mainly to accelerate the aging of the skin. For example, at the same age, farmers who often sunbathe look older than white-collar workers who sit in offices, with rougher facial skin, more wrinkles, more obvious pigmentation, earlier age spots, etc. For small children, how do we protect their delicate skin from the sun? The first and most important thing is to reduce the amount of time in the sun. For our outdoor activities, we avoid the period from 11 a.m. to 2 p.m. as much as possible, because the UV rays are strongest during this time. Second, must be in the sun when the activity, be sure to bring a broad-brimmed sun hat; wear long-sleeved clothes; best to choose in the sun can not be direct sunlight environment, such as under the eaves, trees, umbrellas and so on, to avoid direct exposure of skin in the sun. Third, the correct choice of clothes can also reduce the damage of ultraviolet rays. All clothes have the function of sun protection, but different colors and fabrics, the effect of sun protection is very different. In terms of color, red is the most able to stop ultraviolet light, because the red wavelength is the longest, the broadest range of absorption spectrum, the most sunscreen; dark clothes than light sunscreen, white is the worst sunscreen color. In terms of fabrics, chemical fiber fabrics have the strongest ability to reflect UV rays, including polyester fabrics and stronger than acrylic fabrics; in natural fabrics, linen sunscreen effect is better than cotton and silk. Loose clothing allows for more air flow between clothes and skin, making it easier for sweat to evaporate, drier skin, and dry skin has a stronger sun protection function than moist skin. Therefore, it is very necessary to add some loose clothes of linen material to the baby in summer. Fourth, eating more sun-protective foods can also help babies reduce the damage of UV rays. Preferred foods rich in vitamin C. Vitamin C is the “eternal beauty holy grail”, can antioxidant, whitening, in tomatoes, kiwi, strawberries, oranges in a lot of content. Secondly, soy products are rich in phytoestrogens, which have a strong antioxidant effect and can also reduce the damage of UV rays. Finally, drink more water, so that the baby’s skin fully moisturized, to better maintain the baby’s skin barrier function, the skin’s ability to protect against the sun will be stronger. Fifth, choose the right sunscreen. Sunscreen products according to its composition can be divided into physical sunscreen (reflecting UV rays) and chemical sunscreen (absorbing UV rays), the former is mainly titanium dioxide or zinc oxide, a large number of foreign studies have shown that these two ingredients do not penetrate the skin inside, very safe; the latter composition is a lot, mainly using chemical components to absorb UV rays into heat or molecular vibration. Nowadays, many products are mostly synthetic products that contain both. Now some of our friends like to choose products with high sun protection multiples. In fact, the SPF value only indicates the time multiplier to prevent UV burns, each increase in SPF 1 can increase the time of 15 minutes (SPF 20 = 20 * 15 minutes that there are 300 minutes of sunscreen time), SPF value and sunscreen effect is not correlated. And the higher the SPF and PA value, the more sunscreen ingredients their products contain, the greasier and more likely to cause contact dermatitis. Therefore, it is important to choose the correct SFP and PA value products according to your needs. In addition there are several noteworthy places, must be 30 minutes in advance to use sunscreen; sunscreen products need to be 2mg/cm2 thickness to achieve the proper sunscreen effect; SPF10 sunscreen products coated with 2 layers, sunscreen time or SPF10; swimming or sweating more, sunscreen time will be discounted, 1 to 2 hours need to reapply; generally think that the baby 6 months or more to use sunscreen is possible s, but before 6 months we do not have definitive data on the need to use sunscreen. Although we are careful to protect our babies, sunburn can still occur. A mild sunburn is simply redness of the skin, with peeling on the nose, forehead and cheeks later in life. Mild sunburn immediately hide in the shade or other shady places, with cold towels wet compress sunburn, to replenish skin moisture, reduce skin temperature, reduce the role of skin burns; severe sunburn may appear blister, which requires professional dermatologists for anti-inflammatory, soothing and other treatment, in order to reduce sunburn as much as possible. In conclusion, sun protection for infants and children is very important for the health of the skin and requires more attention from mothers.