Abstract: In this paper,the suppression of rice blast disease by mixed planting susceptible varieties of high-quality rice with resistant varieties was studied.With the mixed match I to 1,Wan 35 to Nanbaozao,86 70 to Jian 154 were compared.The disease-controlled effect of neck blast were up to 55. 13%～62.66%,and the yield increased by 11. 93%～19.87%, The examining results to iso- lates and races showed. the races ZB and ZC groups in mixed planting plot were majority,and occu-pied 79.2%,the infecting rate of isolates was decreased by 7.6%, the infecting rate of ZB13 race was reduced more than 54.45%, and the re-infecting rate of ZB13 race was lower than 20.0%. The study showed that effects of controlling blat and increasing yield were significant by using mixed planting rice varieties,because the planting practice reduced the infecting rate of isolates(or race),suppressed the reproduction of the isolates(or races)with strong pathogenicity,and thus reduced their re-infection.