根据1999年以来浙江省不同类型水稻品种的种植面积数据，分析了不同时期浙江的主栽品种数量和品种集聚度等。结果表明，与《种子法》实施前的1999年相比：一是2002年以来浙江省水稻生产上推广应用的品种总数变化不大，但杂交晚稻品种数量逐年增加，常规水稻（除晚籼稻外）品种数量则逐年下降；二是杂交晚籼稻品种集聚度呈下降趋势，常规晚粳稻品种集聚度呈上升趋势；三是杂交晚稻面积占比逐年上升，而常规晚稻面积占晚稻面积比例总体呈下降趋势；四是1999-2013年期间水稻主栽品种已经更新1次以上。

The temporal changes in the number of major cultivars and percentage of production area for the top five cultivars were analyzed according to production area of different types of rice cultivars in Zhejiang province since 1999. Compared to 1999, Which is the former year of the Seed Law of the People's Republic of China implemented, the total number of rice cultivars applied in Zhejiang Province was almost similar since 2002, but the number of hybrid late rice combinations increased gradually, whereas the number of conventional rice cultivars except for late indica rice cultivars declined year by year. The percentage of production area of top five hybrid late indica rice combinations reduced year by year, while that of conventional late japonica rice cultivars increased gradually. The production area of hybrid late japonica rice combinations increased sharply, while that of conventional late japonica rice cultivars reduced dramatically. During the period of 1999-2013, the major  rice cultivar was replaced at least once.