The results showed that in boys the first sign of sexual maturity is the beginning of enlargement of testicles and penis (Re1 - 10years and 8months), and then followed by hair-growing on the pubic area (R1 - 11years and 4months), after that hair-growing on the body (T1 - 11years and 11months), the appearance of hairs at the axillary pit (Ah1 - 12years and 4months) and voice mutation (Mu1 - 13years and 2months). The beginning of breast glands swelling coincides in time with the first stage of facial hair-growing (13years and 3months). The Adam's apple has the latest development (Ad1 - 13years and 7months). In girls, from the south-east Rhodopi Mountains, the puberty starts with the parallel development of mammary glands and hair-growing on the pubic area at the age of 9years and 7months. Then it is the axillary hair-growing (10years and 9months), followed by hair-growing on the body (11years and 8months), while the average age of menarche occurrence is 12years and 3months.
