The female rats at a prepubertal period were introduced to the restored 5 alpha-androgens, namely: 5 alpha-dihydrotestosterone (DHT), 5 alpha-androstane-3 alpha, 17 beta-diol (3 alpha-diol) or 5 alpha-androstane-3 beta, 17 beta-diol (3 beta-diol) in the dose of 5 mg/100 g. Both DHT and 3 alpha-diol have been determined to induce the vaginal opening as the initial stage of puberty. Stimulation of the puberty in those rats was followed with an activation of both endocrine and generative functions of the ovaries. DHT inhibited the gonadotrophic activity of the hypophysis that delayed the ovulation as the final stage of puberty. The DHT metabolite 3 alpha-diol hastened the first ovulation, while 3 beta-diol did not influence the pace of the puberty. The stimulating effect of DHT at the initial stage of the pubescence in the female rats has been suggested to be due to its conversion into 3 alpha-diol which is likely to be one of the key factors in the pubescence control in rats.