AbstractThe perinatal period is critical for phenotypic plasticity in animals. Numerous physiological and environmental factors could chronically modify animals’ growth and metabolic phenotype. Parental effects are a major driver of phenotypic plasticity. The present study was designed to explore the effects of parental body-mass on offspring growth, body-mass and energy metabolism in Brandt's voles (Lasiopodomys brandtii). The offspring (litter sizes from 6 to 8) from high body-mass parents (female, 51.5 ± 1.6 g; male, 60.4 ± 2.5 g) were defined as parental high group (HBM), and those from low body-mass parents (female, 35.5 g ± 1.2 g; male, 49.6 g± 2.8 g) as parental low group (LBM). Body mass and energy intake from age of 4 weeks to 13 weeks, resting metabolic rate (RMR), nonshivering thermogenesis (NST), glucose tolerance, body composition, organ mass, and serum leptin concentration in the adults were recorded. Our results showed that:（1）gross energy intake and digestible energy intake of offspring in the LBM group were significantly higher than those of the HBM group. The wet and dry masses of testes in the LBM group were significantly lower than those of the HBM group.（2） RMR in the LBM group was significantly higher than that of the HBM group in male offspring. （3）No significant differences in body-mass, NST, serum leptin, and glucose tolerance were detected between these two groups. These results suggest that low parental body-mass resulted in the trade-off between growth and reproduction in male offspring, indicative of the increases in RMR and energy intake but the depression of reproductive organs.