1599 The interference of maturation in physiological response generally do not present similar association in this period, mainly due to changes in physical fitness profile. Moreover, the muscle anaerobic and strength index seems be negatively influenced. Thus the aim of this study was to verify the impact of sexuai maturation on limb strength and muscle power of girls from low socioeconomic status. There were evaluated 42 girls from the Ilhabela Growth Study from 12 to 25 years of age (×: 14.95 ± 3.57). They were divided in two groups according to the self-assessment of breast development (B) and pubic hair (PH) throughout Tanner Stages following Matsudo, S., (1994), procedures. Pubertal group (PUB): 30 girls and Post-pubertal group (POST): 12 girls. The physical fitness variables measured were: body weight and height, skinfolds, leg girth (LG), vertical jump test without help of arms (VJ), long jump test (LJ), and High Box test (HB) to measure the lower limb power. The statistical analysis used was student "t" test for independent samples with p<.01 as level of significance: (Table)TableThe data analysis evidenced a significant increase in LG between PUB and POST groups with 8.71%. On the other hand, jump performance decreased 15.08% in HB comparing the groups, suggesting a negative influence of maturation process to anaerobic response. These results might be indicating that the increase in body weight in 20.27% and skinfolds in 36.90% from PUB to POST groups period would partially explain the decrease in jump capacity, despite of muscle leg increase (8.71%).