The study was performed on male rats with normal rate of aging (Wistar) and senescence-accelerated OXYS rats. Sexual motivation behaviour, activation of endocrine testicle function under condition of sexual activation, gravimetric rates were studied in male rats of different age. Potential ability to spermatogenesis in testis was studied in 14-month male rats. Males underwent the partition test: a receptive female was introduced into the male's cage, but the male and female were separated by a transparent partition. The number of approaches to the partition and total time spent near partition during the test served as an index of sexual motivation. Activation of hypothalamic-pituitary-testicular complex was estimated by plasma testosterone level. A decrease of sexual motivation in the 14-month OXYS males was observed in comparison both with 3- and 6-month OXYS rats and with 14-month Wistar rats. However, no decrease in hormonal component of sexual arousal in aged OXYS males rats was detected. No interstrain differences in potential ability to spermatogenesis in 14-month rats were observed. However, no interstrain differences in the weights of androgen-dependent reproductive organs (testes and preputial glands) were observed under 18-month age. However, the weight of epididymisis in 24-month OXYS rats was significantly smaller than in Wistar rats.