The research results of marker aided selection (MAS) for resistant varieties and lines against rice gall midge Orseolia oryzae Wood-Mason successfully in 1999-2002 were reported in the present paper. The molecular markers linked to the gene Gm6 against rice gall midge were used to select and breed the resistant varieties and lines. The RAPD marker OPM06 was used to verify the existence actually of gene Gm6 in ten developed varieties resistant to gall midge such as Duokang1, Duokang2, Kangwen2, Kangwen3, Kangwen5, Duokangzaozhan, Kangwenqinzhan, which were derived from Daqiuqi. For resistance breeding through PCRbased marker aided selection (MAS), the polymorphisms in the resistant and susceptible parents were identified by RG476/AluⅠ and RG476/ScaⅠ respectively. The RAPD marker OPM06 (1.4 kb) was used to identify 15 new resistance lines from F3 lines of Fengyinzhan1/Daqiuqi in 1999. 21 and 7 resistance lines were selected from F4 and F6 lines of KWQZ/Gui99 (restored line of hybrid rice) using RG476/AluⅠin 2000-2001 respectively. The Gm6 gene was transferred into the restored line of hybrid rice. In 2001-2002, RG214/HhaⅠ and G214/ScaⅠ were used for selecting 11 and 5 resistance lines from F3 lines of KWQZ/IR56 and AXZ/KWQZ successfully. The application of the resistance gene through PCR-based marker aided selection is a new and effective approach in resistance breeding.