The aim of the present study was to examine the effects of hypothalamic neuropeptide genes expression on body mass regulation under seasonal variations in Chevrier′s Field Mouse (Apodemus chevrieri). Body mass, body fat mass, food intake, serum leptin levels and hypothalamic neuropeptide neuropeptide Y (NPY), agouti-related peptide (AgRP), pro-opiomelanocortin (POMC) and cocaine and amphetamine regulated transcript peptide (CART) expression were measured in Chevrier′s Field Mouse. Food intake was measured by food equity, body fat was extracted from the dried carcass by ether extraction in a Soxhlet apparatus, hypothalamic neuropeptides genes expression was measured by real-time q-PCR. Data were analyzed using One-way ANOVA or One-way ACNOVA, and associations were judged by Pearson-correlation analysis. The results showed that body mass and body fat mass showed seasonal variations, higher in summer and lower in winter (Fig. 1), and food intake also showed significant seasonal variability, higher in winter and lower in summer (Fig. 1). Serum leptin level also had similar seasonal variation, showing similar trend as body fat mass (Fig. 2), and serum leptin level showed a positive correlation with body fat mass (Fig. 3). Expression of hypothalamic neuropeptide NPY, AgRP, POMC and CART showed significant seasonal differences (Fig. 4). The above results suggest that Chevrier′s Field Mouse reduces body mass, body fat mass, increases food intake to survive in winter under seasonal changes. Leptin may play a regulatory role in body mass by acting on hypothalamic neuropeptide in Chevrier′s Field Mouse.