To evaluate the safety and efficacy of PEG Somatropin Injection in the treatment of children with growth hormone deficiency, as well as to study the feasibility of extending the dosing intervals (once per two weeks) of PEG Somatropin Injection.

Inclusion Criteria:

• Subjects are diagnosed as GHD before starting treatment, according to medical history, clinical symptoms and signs, GH provocation tests and imaging and other examinations:

  1. According to statistical height data of physical development of Chinese children in nine cities in 2005, the height is lower than 3rd percentile growth curve of the same age, same sex normal children;
  2. Height velocity (HV) ≤5.0 cm / yr;
  3. GH provocative tests (with two drugs of different mechanism of action) confirmed plasma GH peak <10.0 ng / ml;
  4. bone age for girl≤9 years old, for Boy≤10 years old, bone age is one year or more later than the actual age, that is the actual age - bone age ≥ 1 year;

• Before puberty (Tanner I stage), age≥3 years old, male or female;

• Subjects have not received hormone therapy within 6 months;

• Subjects is willing and able to cooperate to complete scheduled visits, treatment plans and laboratory tests and other procedures, to sign informed consent.

Exclusion Criteria:

• Dysfunction of liver and kidney (ALT> 2 times the upper limit of normal, Cr> upper limit of normal);
• Patients positive for hepatitis B c-antibody (HBcAb), hepatitis B surface antigen (HBsAg) or hepatitis B e antigen (HBeAg);
• Patients with known hypersensitivity to PEG Somatropin or Somatropin or any other components of the study product;
• Patients with severe cardiopulmonary or hematological diseases, a current or past history of malignant tumors, immunodeficiency diseases, or mental diseases;
• Potential cancer patients (family history);
• Patients with diabetics;
• Patients with other growth disorders, such as Turner's syndrome, sexual physical delayed puberty, Laron syndrome, growth hormone receptor deficiency, girls with slowly growing who did not rule out chromosomal abnormalities;
• Patients with congenital bone dysplasia or scoliosis;
• Subjects took part in other clinical trial study during 3 months;
• Other conditions in which the investigator preclude enrollment into the study.