Objective       To assess the efficiency of recombinant human growth hormone (rhGH) for a long-term therapy for children with idiopathic short stature (ISS).      Methods       Sixty ISS children (21 males and 39 females) were treated with rhGH 0.15 to 0.18 IU/kg daily by subcutaneous injection at periumbilical area or lateral thigh for 1 to 3 years. Changes of height

growth velocity

mean height standard deviation score (SDS)

bone age and predicted adult height before and in every 6 month after therapy were measured. Side effects were evaluated.      Results       With different courses of treatment

the mean growth velocity was increased from (4.51±0.46) cm/year to (10.97±2.53)

(8.11±1.54)cm/year and (7.13±2.07)cm/year respectively for those children treated for 1

2 and 3 years. Mean height SDS was increased form (－2.60±0.57) to (－1.62±0.64)

(－1.29±0.89) and (－0.12±0.45) respectively. Predicted adult height was increased form (151.62±8.46)cm to (157.33±8.50)

(160.72±10.31)cm and (165.81±7.46)cm respectively (P0.05). The growth velocity of ISS children in Tanner stage Ⅰ

Ⅱ and Ⅲ were similar and significantly better than that of the stage Ⅳ. The acceleration of height age was faster than the bone age (P0.05)

whereas the acceleration of bone age was as fast as chronological age (P0.05).      Conclusion       Long-term therapy with rhGH for ISS children is of significant effectiveness in improving growth and increasing prediction adult height. The onset of therapy starting in children in the prepuberty

earlier and middle puberty is more effective than the latter puberty. Long course of rhGH treatment does not advance the puberty and bone age.