The quality of planting japonica varieties and agronomical changes of middle mid-ripe japonica varieties (pedigrees) bred in recent 20 years were analysised, the results showed that high chalkiness rate and large chalkiness degree were main factors of low rice grain quality in Jianghuai region, With the yield increasing, there were the trends that ear numbers per unit decreased, total grain and filled grain numbers per ear increased, grain density got high, plant height increased, ear got short, filled grain rate and 1000-grain weight increased, and growth period became long. The main reseason that caused the yield high was that Filled grain numbers increased. The number of erect- panicle japonica varieties increased, but that of cured-panicle varieties obviously decreased in recent years.