Abstract: In order to research which kind of Pennisetum alopecuroides is suit to be energy plant, the methods of principal component and cluster analysis were applied to research the growth speed, growth characteristics and growth ability at different period of eight Pennisetum alopecuroides in this paper. The results showed that, the new varieties P. purpureum MT-1 was the best breed on growth ability and comprehensive growth characteristics though not very well on growth speed, (P. americanum×P. purpureum)×P. purpureum cv.‘Guimu NO.1’was the second excellent breed and Pennisetum purpureum cv. Mott was the worst breed among eight experimental varieties according to the comprehensive performance. By the experiment, we had ultimately drew the conclusion that P. purpureum MT-1 was the best fit energy plant among all experimental varieties, and sometimes (P. americanum×P. purpureum)×P. purpureum cv.‘Guimu NO.1’could be as the substitute to P. purpureum MT-1.