Objective To investigate the nurse staffing levels and the influencing factors in hemodialysis units in China, and to provide reference for nursing resource management. Methods A total of 4,712 hemodialysis nurses from 1,208 hospitals in 31 provinces/municipalities/autonomous regions in mainland China filled out the self-designed questionnaire. Results Three hundred and forty-seven hospitals (28.7%) had the number of nurses per 10 patients ＜1, and 455 hospitals （37.7%） showed the number of machines per nurse per shift ＞5. The results of logistic regression analysis indicated that hospital location, hospital nature, the number of dialysis treatments per month, hospital level, and the number of machines per nurse per shift were the influencing factors of nurse staffing level defined by the number of nurses per 10 patients ＜1 or not (P＜0.01 for all). The number of nurses per 10 patients and the number of dialysis treatments per month were the main factors affecting nurse staffing level measured by the number of machines per nurse per shift ＞5 or not (P＜0.01 for both). Conclusion Inadequate nurse staffing was seen in hemodialysis units in China, and nurses worked in excess of the standard patients. It is recommended to add more nurses and ensure nurse staffing on the shift, thus to reduce nurses′ work stress and guarantee nursing quality and patient safety.