Four compounds were isolated from the rhizome of Belamcanda chinensis (Iridaceae) by repeated column chromatography and were elucidated as iristectorigenin A, irigenin, tectorigenin and tectoridin by spectral analysis. The estrogenic activity of these isoflavones was tested using Ishikawa cells. Irigenin, tectorigenin and tectoridin were highly estrogenic ($EC_{50};=;0.75$, 0.42 and $0.81;{mu}g/ml$, respectively), while iristectorigenin A exhibited weak estrogenic activity ($EC_{50}{geq}4;{mu}g/ml$).