Background and aims <p>The prevalence and impact on physical function of osteosarcopenia in the Chinese population remain unclear. The purpose of this study was to assess the prevalence of osteosarcopenia and its association with physical function in the elderly population of China.</p> Methods and results <p>A total of 519 participants (327 males, 192 females; mean age: 67.2 years) elderly people were recruited. Physical performance was evaluated using the Timed Up and Go test and the Short Physical Performance Battery (SPPB). Osteoporosis was diagnosed based on the 1994 WHO criteria, while sarcopenia was defined according to the AWGS guidelines. Osteosarcopenia was diagnosed when both sarcopenia and osteoporosis were present. Among the participants, osteosarcopenia was identified in 27 (5.20%), sarcopenia-alone in 6 (1.16%), and osteoporosis-alone in 257 (49.52%). Logistic regression analysis revealed that age (OR = 1.188, 95% CI: 1.085–1.300) and insufficient exercise (&lt; 30&#xa0;min/day) (OR = 5.606, 95% CI: 1.591–19.762) were significant associated factors for osteosarcopenia. Conversely, body mass index (OR = 0.569, 95% CI: 0.440–0.736), basal metabolic rate (OR = 0.992, 95% CI: 0.989–0.996), and weekly egg consumption (OR = 0.713, 95% CI: 0.564–0.900) were negatively associated with osteosarcopenia. Regarding physical function, individuals with osteosarcopenia exhibited significantly poorer physical performance, including longer times in the five-repetition sit-to-stand test, slower TUG times, reduced handgrip strength, lower SPPB scores, and slower gait speeds (<i>P</i> &lt; 0.01–<i>P</i> &lt; 0.001).</p> Conclusion <p>This study highlights the prevalence of osteosarcopenia and its impact on physical function in the elderly Chinese population. It identifies key associated factors that could guide the early recognition, diagnosis, and management of osteosarcopenia in China.</p>