In order to clear and definite the different pathoogenicity of clubroot from regions all over
China，this paper classified the physiological races and pathotypes of clubroot in 20 Chinese cabbages collected
from all over the country，using Williamms identification system and 4 Chinese cabbage varieties with different
resistances to clubroot．The results of using Williamms identification system showed that 18 Chinese cabbage
varieties were belonged to No.4 physilogical race，and 2 were belonged to No.2 physilogical race．The result
of identifying 4 Chinese cabbage varieties showed that according to their different pathogenicities，they were
divided into 6 types．There were 6 types existing in No.4 physilogical race and 2 types in No.2 physilogical
race．The paper deems that the Williams identification system has not been able to precisely divide the
physilogical race of Chinese cabbage clubroot pathogen，and it is of important significance to study on
screening Chinese cabbage varieties（lines）with different disease resistances and identifying clubroot pathogen
pathotypes．