In the treatment of allergic rhinitis, desensitization is one of the most effective method. But there is a lot of problems in evaluation of the therapeutic effect of nasal allergy in this method. The authors have observed changes in follow up check of various data in 84 patiens after desensitization in order to assess how valuable these changes are as direct evidence of therapeutic effect. Eosinophil count of peripheral blood, serum IgE, IgG and nasal provocation test with House Dust, D. farinae are checked to 6th months after desensitization and following results are obtained : 1) After desensitization, 65% of patients showed statistical decrease in peripheral blood eosinophil count. 2) After desensitization, the change of eosinophil count show statistic decrease in the case of antigen, especially house dust and D. farinae with other antigen. 3) In the age group of 11 to 20, the mean serum IgG was increased with statistical significancy. In the other age group, there was increased IgG level after desensitization without statistical significancy. 4) The mean serum IgE level according to antigen was decreased in the group of H.D, D.F, and H.D+D.F+Others with statistical significancy after desensitization. 5) In the group of H.D and H.D+other antigen, the mean serum IgG level showed increase after desensitization with statistical significancy, but in the other groups of antigen showed increase without statistical significancy. 6) The value of nasal provocation test decreased in the groups of H.D, H.D+D.F, H.D+others, D.F+others, others without statistical significancy after desensitization.