To supplement ecological data of brown rat population in farmhouses in the southern region of Xinjiang and to provide a theoretical basis for predicting population dynamics and implementing scientific control measures, a standardized trapping protocol integrating fixed-point snap-trap deployment and live-cage trapping was implemented across rural households in Kashgar Prefecture in 2019-2025. A total of 718 morphologically valid specimens (comprising both sexes) were collected. Five core biometric parameters, including body weight, head-body length, tail length, hind foot length, and ear height, were measured with precision, and intergroup comparisons (by sex, age class, and season) were conducted using appropriate statistical analyses. The results showed that body weight in the sampled population exhibited a unimodal, approximately normal distribution, with 83.43% of individuals falling within the 40.01-270.00 g range; the modal interval (80.01-240.00 g) accounted for 60.45% of all specimens. Age structure was dominated by adult group I, adult group II, and elderly individuals, collectively representing 69.47% of the sample. No statistically significant sexual dimorphism was observed for any of the five measured morphometric traits (all P>0.05). In contrast, highly significant differences were detected across age classes (all P<0.01), and seasonal variation exerted a statistically significant influence on body size parameters (P<0.05). Under shared environmental conditions in rural Kashgar households, male and female R. norvegicus exhibit comparable growth trajectories and convergent somatic development with advancing age. Seasonal environmental fluctuations significantly modulate growth and morphological maturation. These findings establish a quantitative baseline for future investigations into the seasonal reproductive characteristics of R. norvegicus in rural Xinjiang and provide empirical support for spatially and temporally refined rodent control interventions.