Castanopsis orthacantha and Castanopsis delavayi forests are the major types of semi humid evergreen broadleaved forest in the area of central Yunnan plateau.The paper discusses the interspecific association of the two communities at Jizu Mountain of Yunnan Province.In the study,there are 215 species pairs correlations expressed in 682 pairs mated by 17 tree species,15 shrubs and 29 herbs.The result shows that :1)The species expressed a positive correlation in the same community,and a negative corr...