昆明小鼠（ＫＭ）在我国广泛饲养和应用已有四十余年的历史。该鼠具有繁殖力高和适应性强的特点。我厂用于药品检定的小鼠，系１９９２年从上海生物制品研究所引进的昆明种鼠，在设施、管理等较为重视的情况下，进行小规模饲育。为了防止近亲繁殖，作者选择了分组交配用于育种的方法，将种鼠随机均分三组，采用组间交叉配种的方式。历时五年，已繁殖八代，其繁殖力始终保持在原有较高的水平，每胎平均产仔十只以上 Kunming mice (KM) has been widely reared and applied in our country for more than 40 years. The mouse has the characteristics of high fertility and adaptability. I plant for drug testing of mice, the Department of Biological Products in Shanghai in 1992 from the introduction of Kunming rats, more emphasis on facilities, management, etc., for small-scale breeding. In order to prevent inbreeding, the authors chose a method of grouping matings for breeding. The animals were randomly divided into three groups, and groups were crossed with each other. Lasted five years, has been breeding eight generations, its fecundity has always been maintained at the original higher level, the average litter size per born more than 10