We have studied the effect of new ligands of progesterone receptors, including pregna-D'-pentaran 6-methoxyimino-16a,17a-cyclohexanopregn-4-en-3,20-dio-ne (K1047), 17a-acetoxy-3b-butanoyloxy-6-methylpregna-4,6-dien-20-one (buterol), progesterone (P4), and medroxyprogesterone acetate on the viability of HeLa cells and expression of estrogen receptor-alpha (Era) mRNA gene in these cells. K1I047 and buterol exhibited high cytostatic activity, which exceeded the activity of reference compounds on the average by 15% (p < 0.05). Both buterol and K-1047 (at 10(-6)M) effectively suppressed ERa mRNA gene expression in HeLa cell culture by 83.4 - 9 8.6%.