Abstract: The niche breadth and niche overlapping of 24 dominant species in Cotinus coggygria var. pubescens communities in Zhongtiao Mountains,Shanxi were studied by using Shannon-Wiener’s index and Pianka’s index. The results indicated that the niche breadths of C. coggygria var. pubescens and Rosa xanthina were the biggest,which directly reflected their dominant positions as constructives in C. coggygria var. pubescens communities. The overlapping of C. coggygria var. pubescens and R. xanthina was the biggest among all of species,and the reason was that they were both in the first subshell of the shrub layer and they shared resources in the similar way which approved their occupation on sufficient natural resources. Moreover,the specific overlapping between C. coggygria var. pubescens and Artemisia branyliba was bigger than that on other pair-species because they occupied different sub-layer in the communities and were sun plants that resulted in competition for light resource. The overlapping among species in the shrub layers were more than that in the herb layer,it resulted from that there were more different ecological characteristics among the herbs.

Key words: Cotinus coggygria var. pubescens community, dominant population, niche breadth, niche overlapping, Zhongtiao Mountains