Abstract: The grey related degree analysis was employed to investigate the relationship of biomass and some main characters of the thirsty forage maize varieties. The resucts showed that therelated degree order of biomass and main traits was plant high>ear high>being green to riping>row number>kernels per row>fertility length>silking stage>ear length>seed yield>weight per 1000 kernels；the related degree order of seed yield and the main trait was weight per 1000 kernels>ear length>fertility length>row number>ear diameter>kernels per row>biomass>plant high>ear high>being green to riping>silking stage.