Using sea-island cotton 7124 (R1) and Pima 90 (R2) as rootstocks,grafted seedlings S1/R1, S2/R1,S1/R2 and S2/R2 were obtained by the close-joining method with Jimian 11 (S1) and Emian 22 (S2) as the scion.All the grafting survival rates are above 60%,and the survival ratio of S2/R2 reached 85%.Results confirmed that there was favorable affinity among the selected sea-island cotton and upland cotton varieties.The resistance test showed that the grafted seedlings of S1/R1, S2/R1, S1/R2,and S2/R2 were resistant to Verticillium wilt with the relative disease indexes of resistance at 16.1,12.3,5.4 and 4.5,respectively.The results indicated that susceptible upland cotton cultivars grafting on appropriate disease-resistant rootstocks can effectively control the Verticillium wilt.The physiological indexes of rootstocks,scion and grafted seedlings were determined on the third day after inoculation of Verticillium dahhae Kleb..It was found that the activities of SOD and POD in all leaves were enhanced with MDA content increased.The SOD and POD activities in rootstocks leaves were the highest (the SOD and POD activities in R2 leaves are 68.51 and 661.26 U/(mg·min),respectively),and the increased amplitudes are 31.5% and 27.7%,respectively; the SOD and POD activities in scion leaves were the lowest (the SOD activity in S1 leaves and POD activity in S2 leaves are 40.80 and 424.48 U/(mg·min),respectively),and the increased amplitudes are 15.5% and 5.2%,respectively; the SOD and POD activities in four grafted seedlings leaves were between them.While the MDA contents in leaves were in the contrast:the MDA contents in scion leaves being the highest,and those in rootstock leaves being the lowest,the MDA contents in grafted seedlings leaves being mediate.The enhancement of disease-resistance in plant by grafting can be contributed to the enhancement of the enzyme system which defenses the damage from free radicals and reactive oxygen through reducing the lipid peroxidation in the leaf cell membrane.PAL activity in the leaves of cotton seedling infected by pathogen was significantly elevated and showed regular changes.PAL activity increased slowly in primarily infected the first day followed by a sharp rise,and the activity peak arose at the 3rd day after infection followed by a rapid decline,then the enzyme activity were close to the initial levels at the 5th day PAL activities in different resistant varieties are significantly different.PAL activity in Emian 22(S2) increases slowly with small peak(32.41 U/(mg·min)); PAL activity in Pima 90(R2) increases quickly with high peak value (53.65 U/(mg·min)); PAL activity in grafted cotton seedlings S2/R2 is mediate,and the peak value (46.13 U/(mg·min)) is more close to that of R2.