Background <p>Sleep is necessary for survival, and daytime napping is a common habit for health. However, associations between nighttime sleeping and daytime napping with motoric cognitive risk syndrome (MCR) have not been thoroughly explored, especially in less developed countries. This study aims to examine cross-sectional and longitudinal associations between nighttime sleep duration and daytime napping with the risk of MCR among older Chinese people.</p> Methods <p>A cohort of 4332 individuals who were 60 or older was recruited from the China Health and Retirement Longitudinal Study (CHARLS) and followed up from 2011 to 2015. Self-reported questionnaires were used to evaluate nighttime sleep and daytime napping variables. MCR was subjective cognitive complaints and objective slow gait speed without mobility disability or dementia. The Cox proportional hazard model was used to estimate the longitudinal associations between sleep-related variables and incident MCR. The multivariable logistic regression model was used to examine the cross-sectional associations.</p> Results <p>A total of 695 individuals developed MCR during follow-up years. Compared to moderate sleep (6–8&#xa0;h/night) duration, short sleep (&lt; 6&#xa0;h/night) duration and long sleep (&gt;8&#xa0;h/night) durations increased the risk of incident MCR (&lt; 6&#xa0;h HR = 1.40, 95% CI = 1.19–1.64; &gt;8&#xa0;h HR = 1.39, 95% CI = 1.10–1.75). Moreover, in the adjusted logistic models, a cross-sectional correlation was observed between daytime napping and MCR risk (30–89&#xa0;min OR = 0.70, 95% CI = 0.57–0.85; &gt;=90&#xa0;min OR = 0.74, 95% CI = 0.58–0.95), but there was no significant longitudinal association.</p> Conclusions <p>Short or long nighttime sleep duration(&lt; 6 h/night or ＞ 8 h/night) increased the risk of incident MCR in older people in China. </p>