Ten year old boys growing beard generally belong to the normal puberty development. Boys precocious puberty is at the age of nine years old began to appear the development of secondary sexual characteristics, the main manifestations of height and weight rapid growth, testicular volume increase, penis growth and thickening, the appearance of beard, pubic hair and so on. If the development of secondary sexual characteristics starts at the age of ten, and at the same time there is the case of growing a beard, or simply have a long beard, and no other secondary sexual characteristics, consider the beginning of puberty as a sign of development, and does not belong to the precocious puberty. If there is an increase in testicular size and the development of secondary sexual characteristics before the age of ten, and the beard starts to grow at the age of ten, it may be a symptom of precocious puberty. Try to take your child to the hospital to rule out precocious puberty.