As a developmental milestone, puberty is notable for its rapid and near-simultaneous transformation across biological, social, and psychological domains. As physical appearance matures, individuals must navigate changing social norms and expectations. This often necessitates a confrontation and, perhaps, reorganization of identity and self-perception. Aberrance in maturational timing seems to increase risk for emotional and behavioral problems during adolescence and early adulthood. In particular, girls who mature earlier than their peers seem to find pubertal adjustment especially challenging and are more likely to experience detrimental sequelae. The negative outcomes associated with early pubertal timing span multiple domains. These include psychological, medical, sexual, social, and academic correlates. The present research was to explore the influence of timing of puberty on girls’ self-concept. According to cluster sampling principle, 658 girls aged from 12 to 14 years old were investigated with the Pubertal Development Scale (PDS) and the Tennessee Self-Concept Scale (TSCS). The Results found that:①More than 90% of the 12 to 14-year-old girls are in midpubertal and late pubertal stage, and few girls are in prepubertal and postpubertal stage; ②The results of two-factor variance analysis showed that, there were no main effects of age and pubertal stage on all factor scores and the total score of TSCS; ③The interaction of age and pubertal stage was apparent on Family self, Social self, Self identity, Self action, and the total score of TSCS, the girls at low pubertal stages and high ages, and those at high pubertal stages and low ages, get significantly lower scores. The research showed that too late or too early puberty timing might both have negative effect on girl’s self-concept development. Further research should attempt to elucidate the mechanisms by which early maturation afects the adolescent girl’s self-concept development.