The experiment was carried out by ‘Xinxiaqing 2’ and ‘Xinaiqing’ in climate chambers and studied the influence of seeding growth,physiochemical substance and active oxygen metabolism between the infection clubroot disease (level 3) and not affected clubroot disease (level 0) in pak-choi(Brassica campestris ssp.chinensis Makino) by being taken artificial inoculation method.The results showed that:(1)after infected clubroot disease,pak-choi-seedling growth,the shoot fresh weight and the chlorophyll content decreased;while the ratio of root-top(R/T) increased.With more seriously infected clubroot disease,the seeding-growth was restrained significantly,and ‘Xinxiaqing 2’ was more seriously than ‘Xinaiqing’.(2)The osmoprotectants,such as soluble protein,soluble sugar,free amino acid in leaves and proline in roots and leaves decreased,while the malondialdehyde (MDA) content in leaves and roots increased.The changes of osmoprotectants in ‘Xinxiaqing 2’ infected clubroot disease were larger except free amino acid content.(3)The NO₃^- content,activities of nitrate reductase(NR) and glutamine synthetase(GS) of plants infected disease become low.(4)Under clubroot disease stress,the superoxide dismutase (SOD),peroxidase enzyme (POD),catalase (CAT) and ascorbic acid peroxidase (APX) activities in leaves were also decreased,and the SOD,POD and CAT activities in roots were reduced more than that in leaves.Except CAT,the reduced degree of ‘Xinaiqing’ was blower than ‘Xinxiaqing 2’.Obviously,the osmoprotectants content,active oxygen metabolism,ability of using nitrogen and light were affected by clubroot disease,and membrane lipid peroxide were increased.All of the above,it was found that ‘Xinxiaqing 2’ was more seriously influenced by the clubroot disease than ‘Xinaiqing’,and the ability of photosynthesis,absorption,antioxidant and osmoprotic adjustment was depressed by clubroot disease,and the whole plant was sick to grow.Soluble protein and MDA contents,the activities of antioxidant enzymes can be used as early screening physiological indexes of clubroot disease.Comparing with normal plants,clubroot disease resistance of ‘Xinaiqing’ was higher than ‘Xinxiaqing 2’.