Objective To investigate the efficacy and the course of desensitization treatment in bronchial asthma with positive specific IgE to dust mite in children. Methods A total of 105 children with bronchial asthma with positive specific IgE to dermatophagoides farinae allergens were randomized into the observation group and the control group. Children in the control group were treated to continue anti-asthma according to the routine of prevention and treatment children with asthma. Chinldren in the observation group were treated by dermatophagoides farinae drops in addition to the treatment of children in the control group. The recurrence of asthma was compared between two groups at 25 weeks post-treatment. At 25 weeks post-treatment , children in the observation group was randomly divided into the observation groupⅠand group Ⅱ. Children in the observation groupⅠreceived continuous treatment except for desensitization treatment. Children in the observation group II received the sublingual immunotherapy with dermatophagoides farinae drops (No.4) for 1 year in addition to the treatment in the observation groupⅠ. The recurrence of asthma was also compared between the two sub-groups. Results The rate and times of recurrence of asthma were lower in the observation group than those in the control group(P < 0.05), with no significant differences between the observation groupⅠand groupⅡ (P > 0.05). Conclusion The recurrent rate and frequency of asthma could be reduced by the sublingual immunotherapy with dermatophagoides farinae drops in children with asthma of positive specific IgE to dust mite. The course of treatment may be half year long.