Through investigation research, occurrence of maize stalk rot in Guangxi and effect of occurrence ofthe disease at different stage on maize yield components was mastered. This provided the theoretical guidance basisfor the prevention and control the diseases. Method: selected fixed point in major corn producing areas of Guangxiand did diseases epidemic investigation, then calculated the average incidence. For different onset period of corn,harvested after mature and measured the yield. At last, statistical analysis was done. The results showed that maizestalk rot occurred in major corn producing areas of Guangxi to some extent. The incidence of disease on the autumnmaize was 3.5% to 10.3%, while the onset on spring maize was lighter, which incidence of disease was 0.4% to 9.8%. There were differences in disease resistance of different varieties. The best disease resistant variety was Zha-ofeng 688, whereas the worst disease resistant variety was Liyu 16. But resistance of the same variety was differentin different places. Onset period of the disease affected maize yield components to a significant or extremely signifi-cant level. Conclusions: Maize stalk rot was widespread, and the disease epidemic trend was that disease of autumnmaize was more serious than spring corn. Southern maize varieties was more resistant than northern maize varieties.The earlier the onset period, the greater the effect on maize yield components.