Personality reflects an individual’s set of typical behavioral tendencies exhibited in various situations and refer to animal’s stable and heritable behavioral characteristics. The constraint hypothesis assumes that personality is heritable, is determined by genetic factors, and does not evolve easily. In contrast, the adaptive hypothesis assumes that personality is mainly affected by environmental factors. Personality traits of different species in the same environment will produce convergence. To examine the predictions of the constraint hypothesis and adaptive hypothesis, we compared personality differences in plateau pika(Ochotona curzoniae) between two different regions. The results of cluster analysis show that the personality of wild plateau pika populations from Gangcha County clustered into 3 categories, Maqin County clustered into 2, and after rearing 2-3 months in laboratory, personality of plateau pika from both counties clustered into 1 category. Scanning, climbing, centrality, border behavior of two geographical populations showed no significant difference, but immobility between geographic populations still showed significant differences, the ambulation between two geographic populations and wild, interior populations both showed significant differences. No significant difference was found in docility between two geographic populations; there was no significant difference between geographical populations for heart rate. The results indicate that there are no significant geographical differences in major behavioral parameters of plateau pika personality traits. So personality is determined by genetic factors and confirmed the prediction of constraint hypothesis.