Abstract: In order to develop the wheat-corn-rice triple cropping system in Yangtze River delta region,the ecological principles for high and stable yield of this cropping system were systematically analyzed, based on field experiments and investigations. It was found that the local weather andsoil conditions were suitable to the growth of spring corn, the interspecific relationship inwheat-corn intercropping was mainly mutually beneficial, the agricultural resource in triplecropping system could be more effectively utilized by 20%, the soil phpeical properties and fieldecoogical environment could be improved, and soil fertility could be maintained by returnmgcorn straw into soil and the triple cropping system was tolerant to successive cropping. All ofthese consist of the basis of high and stable vield.

Key words: Yangtze River delta region, Wheat-corn-rice triple cropping system