Abstract: Primary isolation of allelochemicals from Chinese fir，Castanopsis rgesii and Schima superba and the bioassary of Chinese-fir seeds were carried out in this paper．The result showed that after Chinese fir，Castanopsis fargesii and Schima superba’s leaves dissolved by propanone and ethyl acetate，the allelochemicals of Castanopsis rgesii and Schima superba distilled by ethand shsolute represented more active than those of distilled by petroleum， the allelochemicals of Chinese fir distilled by petroleum represented more active than those of distilled by ethand shsolute．It could confirm that allelochemicals of Castanopsis rgesii and Schima superba were polar allelochemicals，allelochemicals of Chinese fir were little-polar allelochemicals．