Abstract：The effects of chlorine dioxide on controlling cucumber（Cucumis sativus L.）Fusarium wilt and cucumber growth were studied．The results indicated that cucumber Fusarium wilt could be controlled effectively by chlorine dioxide and the control effect became much better with the increase of chlorine dioxide concentration．The control mechanism was further studied and it showed that chlorine dioxide could kill microorganism in soil and the pathogen of cucumber Fusarium wilt strongly．When chlorine dioxide was contacted directly with seed in a petri dish，it did not show any negative effect on seed germination at low concentration，and seed vigor and bud weight were normal．When the concentration got higher，its inhibiting effect on cucumber seed germination appeared．The inhibiting concentration decreased，if seed was pretreated with forced sprouting methods before treated with chlorine dioxide．In the pot-experiment，after the soil watered with chlorine dioxide，chlorine dioxide did not damage the growth of cucumber seedling at higher concentration of 500 mg?L-1，and control effect of cucumber Fusarium wilt was 96.4%.
