Polymorphism of 49A/G gene CTLA4 in 44 patients with allergic rhinitis and 70 conditioned healthy donors of Uzbek population has been analyzed. The "unfavourable allele" rate in general studied groups and control groups did not practically differ and was 73,3 and 72,9% correspondingly. The analysis of distribution of polymorphism 49A/G gene CTLA4 among the patients of the groups with allergic rhinitis depended on currency (seasonal form) and gender, while in the control groups statistical significant differences were not revealed. However, in patients with annually forms of allergic rhinitis the rate of functional "unfavourable allele" 49A/G gene CTLA4 increased in 1,3 times in comparison with the group with seasonal form and slightly in the control group.