测定了9个地区159只小家鼠的尾长率，发现小家鼠尾长率与其所在地区的年平均气温具有极强的正相关（r=0.96），尾长率与气温的回归方程为y=1.45x+63.75。处于寒冷、温暖与炎热地区小家鼠的尾长率三者间差异极显著。探讨了小家鼠尾长率变化的机理和我国小家鼠种下分类十分复杂的原因。

The tail ratios of 159 mice from 9 regions in China were measured. It is clear that the tail ratios of mice are closely correlated with the average air temperature in a year in their living region (r=0.96 y=1.45x+63,75). There are significant differences in the tail ratios among mice from cold, warm and hot region (P＜0.01). The mechanism of tail length variation and the causes of the complicity of subspecies classification of mice were discussed.