Potato is an important crop in mountainous areas of China, such as Chongqing. Late blight (LB) caused by Phytophthora infestans has been a major threat to sustainable potato production in China. Growing disease-resistant varieties is the most economical, effective and environmentally friendly way to control LB in potato production. In order to understand the composition of resistance (R) genes to late blight from different germplasms and to obtain potato varieties (lines) with resistance to LB in Chongqing, screening of R genes using molecular marker linked to LB and evaluation of LB resistance upon natural and artificial inoculations were carried out in 218 potato varieties (lines) from different regions. The results showed that six R genes were detected in the tested genotypes and the composition of the molecular markers could mainly be divided into four types, including Type I, which was characterized by the presence of a broad-spectrum resistance gene RB; Type III, which was characterized by the absence of R2 family markers, most of which were susceptible to late blight; Type II and IV, which were characterized by three R genes (R2 Family+R3a+R3b) and four R genes (R1+R2 Family+R3a+R3b) marker types, respectively, which showed a certain proportion of LB resistance in these two types. The proportion of resistance in type IV was higher than that in type II. These results suggested that genotypes containing RB gene markers positively contributed to LB resistance. Screening of these gene markers will help to improve the breeding efficiency of LB resistance in Chongqing. By analyzingR genes compositions of and LB resistance tests in 218 potato genotypes, this study provided scientific basis for the future popularization and application of new varieties (lines) and resistance breeding in Chongqing, and also provided genetic resources for the discovery of new R genes.