Objective To investigate the expressions ofTestosterone in the condylar cartilage of rapid growing rats.Methods The mimic functional appliances were used in experiment groups and rats were killed after 3 days , 1week, 2weeks, 3weeks and 4weeks. Immunohistochemical technique was used to detect the expression ofT.Results Twas expressed throughout the condy- lar cartilage. TheHighest expressionswere in mature layers of both experiment and control groups. Alongwith the maturation, the expressions of T in the condylar cartilage were changed respectively, and the immunostain levels in the mature layer of experiment groups 2 and 3 weekswere higherthan those of control groups (P
