【Objective】 To compare the influences in osteoblasts of infants and toddlers by short-term therapy of the three kinds of glucocorticoids (hydrocortisone,methylprednisolone and dexamethasone). 【Methods 】 Thirty children suffered from bronchiolitis were divided into three groups by different kinds of glucocorticoids:the hydrocortisone group,the dosage was 10 mg/(kg·d),the methylprednisolone group,the dosage was 3~5 mg/(kg·d) and the dexamethasone group,the dosage was 0.25~0.5 mg/(kg·d).The courses of treatment were all 5 days.The serum concentrations of bone alkaline phosphatase (BAP)and total alkaline phosphatase (TAP) were measured. 【Results】 1)The serum levels of BAP and TAP in hydrocortisone group and dexamethasone group before and after the treatment were not different significantly(t=0.292,P＞0.05).2)The serum levels of BAP in methylprednisolone group before and after the treatment were (82.15±25.86)U/L and(57.27±17.53)U/L,respectively.There was significant difference(t=3.947,P＜0.01).The serum levels of TAP in methylprednisolone group before and after the treatment were (149.71±22.22) U/L and (117.00±24.93)U/L,respectively.There was significant difference(t=3.111,P＜0.05).3)There was positive correlation both the serum BAP and TAP (R=0.703,P<0.01). 【Conclusions】 The therapy of short-term routine dosage of methylprednisolone could inhibit the function of osteoblasts in infants and toddlers.The serum TAP may replace BAP to monitoring the function of osteoblasts in period of the therapy of glucocorticoids.Under the same clinical effects,hydrocortisone is recommended vis-a-vis methylprednisolone and dexamethasone.