Abstract: A ecological model O=m/lnV was develpoed to assess host adaptation for fecundity of Bemisia tabaci(Gennaidus),where m=parameters of average eggs within a time period,and V=variance of samples.The model was used to assess the fecundity of whitefly on 37 plant species.The results showed that the whitefly was able to lay eggs on most host plants,and the fecundity of adults was affected by host plants either.37 host plants were classified with clustering analysis into 3 groups: favorite hosts,adaptive hosts and non-adaptive hosts.The results from clustering analysis were not accordant with host-domain hypothesis,because the close relative plants were classified to different clusters.It was found that,in analysis of pair-samples mean comparing,the different bio-type of whitefly showed a significant difference in the host adaptation while the same bio-type whitefly population with different feeding experience showed the quite similar performance.