Abstract: To investigate the relation between activity differences of hydrogen peroxide (H2O2) and its oxidase in different resistance pines inoculated with Bursaphelenchus xylophilus and the resistance of pine trees, the content of H2O2 and the activity dynamic changes of POD and APX were studied. The results showed that the content of H2O2 of Pinus thunbergii ((470.01±47.20)μmol/g) and P.massoniana ((232.33±9.42)μmol/g) was higher than P.taeda ((14546±11 86) μmol/g) at the early stage of inoculation (after 4 hours of inoculation). But the H2O2 of P.taeda go up substantially and go down more slowly after going to its peaks than P.thunbergii and P.massoniana after 72 hours of inoculation. The activity of POD and APX of three pines both had two peaks after inoculated with B.xylophilus, and the value of two activity peaks was P.thunbergii>P.massoniana>P.taeda, and reached the first peak of activity increased rapidly in susceptible pines, the resistance of P.taeda reaching the second peak of activity increased rapidly. This indicated that the different resistance pine trees inoculated with B.xylophilus, the content of H2O2, POD and APX enzyme activity was closely related to differences in their resistance, the accumulation level of H2O2 in the pines had an important influence on pine resisted B.xylophilus.