Abstract: Data from forecast and control of rice diseases during 1995-2012 in Linhai were analyzed in this study to reveal long\|term movement rule of rice diseases after changing from double into single cropping system， which was supposed to be helpful to improve diseases control level. The results showed that there was a gradually aggravated trend in the evolution from the former structure of main rice diseases， sheath blight， blast and bacterial stripe （bacterial blight）， to a structure of sheath blight， black\|streaked dwarf and false smut （panicle blast）. A mathematical model for long\|term diseases movement of sheath blight， black\|streaked dwarf， false smut has been established. Four key points were proposed to control single\|cropping rice diseases， controlling planthoppers to prevent dwarf at seedling stage， managing disease center at tillering stage， three check\|ups for preventing at heading stage， and local prevention for local diseases. Therefore， to ensure super\|high\|yield cultivation of single\|cropping rice， diseases control strategies in single\|cropping system need to be adjusted basing on understanding the diseases movement rules and improving node management technology， rather than timely treating for single disease.

Key words: rice, diseases, motion regularity, mathematical model, control by critical control point