Abstract: Objective To investigate the relationship between sleep quality and nighttime sleep duration and sarcopenia in middle-aged and elderly men （≥ 45 years old）. Methods A cross-sectional study was conducted on 345 hospitalized patients inUrumqi. The Pittsburgh Sleep Quality Index was used to assess sleep quality, and L3 skeletal muscle index was used to diagnose sarcopenia. Univariate Logistic regression was used to analyze the relationship between sleep factors and sarcopenia, and multivariate Logistic regression models were used to explore the relationship between sleep quality and nighttime sleep duration and sarcopenia in middle-aged and elderly men. Results The prevalence of sarcopenia in the included patients was 35.1%. The prevalence of sarcopenia was different among those with different sleep quality and nighttime sleep duration （P < 0.05）. The prevalence of sarcopenia in patients with poor sleep quality and nighttime sleep duration ≤ 6 h was higher than that in the non-sarcopenia group （P < 0.05）. MultivariateLogistic regression analysis showed that, without adjusting for arguments, the prevalence of sarcopenia in men aged 45~<74 years with poor sleep quality was 1.992 times that of those with good sleep quality, and the prevalence of sarcopenia in men aged 45~<74 years with nighttime sleep duration ≤ 6 h was 2.770 times that of those with nighttime sleep duration > 6 h. After adjusting for body mass index, nutrition risk screening 2002, alcohol consumption, smoking, Generalized Anxiety Disorder-7, Patient Health Questionnaire-9, and C-reactive protein levels, the prevalence of sarcopenia in men aged 45~<74 years with poor sleep quality was 4.152 times that of those with good sleep quality, and the prevalence of sarcopenia in men aged 45~<74 years with nighttime sleep duration ≤ 6 h was 3.703times that of those with nighttime sleep duration > 6 h. However, in men aged ≥74 years, there was no statistically significant relationship between sleep quality and nighttime sleep duration and sarcopenia （P > 0.05）. Conclusion In men aged 45~<74 years, poor sleep quality and nighttime sleep duration ≤ 6 h increase the risk of sarcopenia.