Microtia is a relatively common congenital malformation and the only treatment available is external ear reconstruction surgery. The timing of starting ear reconstruction has to be considered from both a psychological and physiological perspective. Microtia is actually a psychological burden on the patient that is difficult to imagine and, of course, this defect is naturally a psychological burden on the parents. at around 3 years of age, children begin to realize that their ears are different on both sides and begin to compare them in the mirror. By the age of 4-5, an awareness of the body has usually developed. The introduction of ridicule by peers when the child goes to school will deeply affect the normal psychological development of the child. Therefore, psychologically, the earlier the surgery is performed, the better, at least before school age. From the physiological aspect, there are two main factors to be involved. On the one hand, the development of the auricle, which is already 85% of the adult size at the age of 3, grows rapidly as a child but slowly as an adult, and after the age of 10, the width of the auricle almost stops growing, and the distance from the ear wheel to the mastoid process remains the same. The length of the auricle grows gradually with age. In children between the ages of 5 and 10, the length of the auricle is only a few millimeters smaller than that of adults, mainly in the cartilage part, while the earlobe part is similar to that of adults. Therefore, if auricular reconstruction is performed during this period, there will be no significant asymmetry between the ears in adulthood. On the other hand, since the auricle is located on both sides of the skull, it is unlikely that a bystander can see both ears at the same time and compare them as if they were two eyes, so even if there is a slight difference in the size of both ears in adulthood, it does not matter much. On the other hand, the current conventional method is to use the patient’s own rib cartilage as the auricular scaffold for the reconstructed ear. In terms of rib cartilage development, it is generally believed that rib cartilage can be sculpted into ear scaffolds in children around the age of 6 years. In foreign countries, the age of surgery is around 6 years old, but it may be necessary to take 3 or more rib cartilages, which is traumatic for the patient and may even affect the development of the thorax. At older ages, it may be possible to remove only 2 ribs of cartilage, which is relatively less invasive. However, after the age of 14 years, the rib cartilage begins to ossify and its flexibility and toughness begin to decrease, which is not conducive to cartilage sculpting and shaping. In summary, it is important to consider both factors, to discuss them carefully with a specialist, and to decide when to start the surgical intervention between the ages of 6 and 12, taking into account the patient’s own characteristics.