The typical rice varieties in Liaoning,Jilin and Heilongjiang provinces from 1970 to 2010 were used as trial materials to analyze the differences,changes and relationships in yield traits of rice released in different provinces and different years. The results showed that the yield of rice in three provinces from 1970s to 1990s increased by 9.66% and decreased slightly in the beginning of 21st century. The yield of rice increases was mainly attributed to the seed number increases. The yield was significantly positively correlated with panicles per hill,grain number per panicle,primary rachis branches number,second rachis branches number,grain number of primary rachis branches,grain number second rachis branches,panicle length,panicle weight,grain density,ratio of secondary branch grains,but negatively correlated with kernel setting rate,kernel-setting rate of primary branch and secondary branch,and except kernel-setting rate of primary branch,others all reached significantly level.