Objective To investigate the serum levels of fibroblast growth factor 23 (FGF23), Klotho, insulin-like growth factor 1 (IGF-1) and sex hormones in girls with idiopathic central precocious puberty (ICPP), and to determine the relationship between serum FGF23, Klotho, IGF-1 and ICPP. Methods Thirty-four girls under 8 years olds who were diagnosed with ICPP in the Department of Pediatrics, Hebei General Hospital from June 2021 to June 2022 were selected as the ICPP group. Twenty-six healthy girls who underwent physical examination in our hospital during the same period, aged less than 8 years, and did not start puberty development were selected as the control group. Serum FGF23, Klotho, IGF-1, sex hormone levels, bone age and ovarian volume of all patients were detected and compared. Results There were significant differences in height (Ht), height standard deviation score (Ht SDS), body mass index (BMI), body mass index standard deviation score (BMI SDS), bone age (BA), bone age index (BAI) and ovarian volume between ICPP group and control group (P < 0.05 ). There were significant differences in LH, FSH and FGF23 between ICPP group and control group (P < 0.05 ). There was a positive correlation between Klotho and FGF23 in ICPP group(r=0.781，P＜0.05), and Klotho was positively correlated with IGF-1, LH value, BMI, bone age and ovarian volume(r=0.646、0.52、0.317、0.413、0.697，all P＜0.05); FGF23 was positively correlated with IGF-1, LH, BMI, bone age and ovarian volume (r=0.591、0.392、0.353、0.41、0.669，all P＜0.05). Conclusion Serum IGF-1, FGF23 and Klotho may play a physiological role in the pubertal development of girls.