Background : The current standard method to diagnose central precocious puberty(CPP) is gonadotropin releasing hormone stimulation test (GnRHST). But, it is inconvenient for children because of time-consuming and multiple samples. This study aimed to present utility of morning basal luteinizing hormone (LH) for the screening of central precocious puberty with emphasis on the influence of diurnal variation. Methods : This study is a retrospective review of 160 female children who were suspected onset of pubertal signs such as breast budding before 8 years of age, and were evaluated using a GnRH stimulation test (GnRHST). And we compared the level of LH, FSH and bone age between CPP and prepubertal group. The prognostic value of single basal gonadotropin levels for screening of central precocious puberty was examined. Results : In the 160 patients, central precocious puberty(CPP) group was 121(75.6%) and prepubertal group was 39(24.3%). The mean concentration of LH at CPP and prepubertal group were 1.01 ± 1.80 IU/L and 0.21±0.28 IU/L respectively (p 0.007). Bone age at CPP group and prepubertal group were 9.3 ±1.09 yr and 9.0 ±1.18 yr (p 0.163). Receiver operating curves (ROC) was used to evaluate the sensitivity and specificity with morning LH levels and 78.5 % and 71.8% respectively. And cut off point of single basal LH levels for screening of central precocious puberty was 1.2IU/L in this study. Conclusion : Our findings suggest that single morning basal LH presents clinical efficacy for screening of central precocious puberty. And bone age advanced over chronological age is not significant in screening of central precocious puberty.