This is a multicenter, randomized, open-labeled, positive controlled phase 2\&3 combined study to evaluate the safety and efficacy of weekly Y-shape pegylated somatropin, compared to daily somatropin (Norditropin®), in prepubertal, treatment-naive children with growth hormone deficiency.

This multicenter, randomized, open-labeled, positive controlled study is divided into two stages. The first one is aimed to exploit the optimal dose of Y-shape pegylated somatropin, while the second one is aimed to confirm the efficacy and safety of the study drug. A total of 400 prepubertal children with growth hormone deficiency were expected to enrolled. Subjects will firstly undergo a 52 weeks treatment, and then followed for 5 weeks.