Abstract:From the significance of the good germplasms for rice breeding,the applied study about the wide cross and polyploidization of cultivar and wild rice in rice breeding was summarized in this paper.Due to the difficulties of wide cross,such as hybrid incompatibility,hybrid sterility derived from traditional interspecific hybridization can use some methods such as hormone treatment,embryo rescue culture to solve them and got new varieties with good characters and heritability.The biochemical and molecular techniques to identify the hybrid were successful in overcoming cross incompatibility and obtaining interspecific and intergenomic hybrids.These advancements proved that the method to combine wide cross with polyploidization would be feasible in rice breeding for getting good rice cultivars.