Abstract: The research was about the effects of enhanced UV-B radiation on chlorophyll content of two wild sugarcane(Saccharum spontaneum L.) clones for two consecutive years in field condition.The results showed that clone 93-25 was more resistent than clone 92-11.Chlorophyll content of clone 92-11 decreased while that of clone 93-25 increased under 5 kJ/m² UV-B radiation.Interspecific difference in chlorophyll content of wide sugarcanes existed.Clone 92-11 was more resistent in 2004 than 2003 while clone 93-25 was opposite change.The clones were more sensitive in their flowering stage than tillering stage,and the elongating stage was the most resistent stage.