Abstract: We collected 329 kinds of plant-seeds. It was found that there were 60 kinds of plant-seeds whose extract solutions could agglutinate human erythrocytes to various extents (the most hemagglutinating titer was 2048x)using agglutination test, neutralization test and absorption test. The extract solutions of 23 kinds of plant-seeds could not be inhibited by saliva-stains using neuyralization test. The extract solutions of some plant-seeds (13/23) could be inhibited by extract solutions of seminal stains. Some (5/23) could be inhibited by extract solutions of bloodstains. The results of absorption test showed that the most of extract solutions of plant-seeds (19/23) could be absorbed by bloodstains. It remains to be further studied whether or not these neutralization tests, inhibition tests and absorption tests are specific and if these planthemagghitinins can be used practically.