The effects of rivanol

glycerol

and propylene glycol with termination of early pregnancy arestudied in 82 rabbits with 515 fetus. The rates of termination with rivanol solution alone are paralleled with the dosages. The effect of 50% glycerol on termination of early pregnancy is much larger than that of 50% propylene glycol (p<0.01); but it is similar to solution of 50% glycerol and propylene glycol (p>0.05). The preparation of rivanol dissolved in glycerol for termination of early pregnancy shows very strong synergism.Viscose coefficient of 50% glycerol and propylene glycol is the largest among destilled warter

50% glycerol

and 50% propylene glycol (p<0.01). The preparation of rivanol dissolved in 50% glycerol and 50% propylene glycol can rise the amount to remainder of rivanol in the uterus of early pregnancy. This intrauterine preparation is suggested useful in the termination of early pregnancy.