1. Subterraneum clover (var. Dwalganup and M. Barker) from Chillán and Cauquenes, Chile, has an estrogenic activity of 1,93 ± 0,84 of diethylstilbestrol per 100 g. of dry matter.
2. Comparing with the accepted scale of activity between oestradiol, the activity determinated in our Subterraneum clover is smaller than the foreing values (5, 6, 11).