Purpose of the current studywas to compare lower extremity (LE) muscular strength including quadriceps, hamstrings, and hip abductors by threedifferent developmental phases (<10 years,11-14 years, and 15-18 years) in pediatric female athletes. A total of 388young female athletes were examined. Significant differences were found in bodymass normalized isometric LE muscle strength by the three developmental phases[quadriceps (p=0.001), hamstrings (p=0.001), and hip abductors (p=0.034)].Pairwise comparisons showed lower body mass normalized isometric LE strength in11-14 years than <10 years in all LEmuscle strength [quadriceps (p=0.001), hamstrings(p=0.001), and hip abductors (p=0.037)]. Also,significantly less body mass normalized isometric strength was detected in15-18 years than <10 years in quadriceps (p=0.001) and hamstrings(p=0.001), but not in hip abductors (p=0.056). Bodymass normalized isometric LE strength (quadriceps, hamstrings, and hipabductors) of 11-14 years females was lower than <10 years females.