Objective To investigate the effect of family factors on asthma control in children. Methods Questionnaire surveys were conducted among 120 asthmatic children between 4~11 years old and their parents by using Family Assessment Device (FAD),Family Environment Scale (FES-CV) and Childhood Asthma Control Questionnaire Test (C-ACT).All the children were divided into three groups according to C-ACT scores:completely controlled group (≥23 points) in 29 cases,partly controlled group (20 to 22 points) 31 cases and uncontrolled group (≤19 points) in 60 cases. Results Besides the achievement orientation,the rest of aspects were significantly different among the three groups.The expressiveness,active recreation orientation in the uncontrolled group were significant lower than those in the partly controlled group and the completely controlled group (separately 4.72±1.32 vs 6.1±1.11 vs 6.97±1.12,5.29±2.10 vs 6.52±1.86 vs 6.52±1.86),but the conflict and control in the uncontrolled group were at high level(P<0.05).The family function of the controlled groups was better than the uncontrolled group.Multiple liner regression analyses showed that the factors of expressiveness,recreational orientation and control of FES-CV scale and the affective involvement and the behavior contro1 of the FAD scale were important factors for asthma control. Conclusion The factors of family environment and family function have significant effects on the asthma control.