中文摘要：

基于联合国COMTRADE数据库提供的HS1996的数据，计算中国、印度和俄罗斯2001和2005年产品的对称显示性比较优势（RSCA）指数。运用统计描述和马尔柯夫转换矩阵，对中国、印度和俄罗斯产品的RSCA部门分布及其演变，以及部门内分布的跨时期变化进行的分析结果表明，中国、印度和俄罗斯绝大多数产品不具有比较优势，比较优势结构没有发生大的变化，贸易模式具有较强的稳定性。相比之下．中国比印度和俄罗斯具有更大的比较优势．俄罗斯的比较优蛰最低。

英文摘要：

Based on data drawn from COMTRADE, RSCA, an improved RCA index, is computed for China, India and Russia for 2001 and 2005. Analysis by means of statistic description, PDF, and Markovian transition matrix suggest that majority of Chinese agricultural products don ＇t have comparative advantage, and as a whole few things were changed during the observation period. However, there are noteworthy changes underlying the rather stable trade pattern.