Abstract: In order to study the development of yield and morphological characteristics of late japonica rice in Zhejiang province, late japonica variety Nongken 58 and its 18 derived varieties were grown at China national research institute farm in Zhejiang province during 2003 and 2004. The results were as follows: (1) the yield of late japonica rice in Zhejiang province increased greatly in 1960 s’, the varieties released at this stage could be divided as large panicle number and numerous grain type or panicle number type, the yield of late japonica rice after 1970s’ increased slowly, most of the varieties released at this stage were large panicle number and numerous grain type. (2) In plant morphological characters, compared to the former varieties (released before 1985), the latter varieties (released between 1985-1995) had short flag leaf length, small leaf original angle, longer third leaf length and wide flag and third leaf width; in stem and panicle characters, the plant height, internode length of the latter varieties were shorter than that of the former varieties, but in term of stem density, sheath weight and grain density per panicle, the latter varieties were larger than the former varieties. (3)Correlate analysis show there were significant negative correlations between length of the upper 2 leaves, original angle, leaf curvature, length of the upper 2 internodes and grain yield, positive correlations exist between 3rd leaf length, leaves width, biomass yield, seed setting rate and yield.

Key words: Late Japonica Rice, Derived Varieties, Yield, Morphological Characters