Abstract: Phoma stem canker, the pathogens are consist of Loptesphaoria maculans and Loptesphaeria biglobesa. Loptesphaeria maculans becomes the major restrict factor for rapeseed industry development worldwide except China and India, which caused serious economic losses in most of the major production areas. We firstly identified Loptesphaeria biglobesa existed diseased plants in 1999 and the occurrence and damage caused by Loptesphaeria biglobesa showed sprawling trend in China, the damage areas expanded to 42 counties of 14 provinces in just dozens of years. But for it did not cause significantly yield loss, there were no enough attention to Phoma stem canker. Study on the occurrence, epidemic and evolution regularity of Phoma stem canker worldwide,we are afraid of Loptesphaeria biglobesa replaced by Loptesphaeria maculans gradually, Loptesphaeria maculans threats to oilseed rape and other cruciforous crops of China.