Background: Nowadays, irrational use of antimicrobials has threatened public health. It's necessary to expand the use of clinical practice guideline (CPG) on antimicrobial for facilitating the proper use of antimicrobial. However, the utilization status of CPG on antimicrobial and the influencing factors, especially the ones at the organizational level, remain largely unknown. Methods: A cross-sectional questionnaire survey was conducted on a sample among physicians from 16 public hospitals in the eastern, central and western parts of China. A multilevel regression model was employed to examine factors associated with physicians' utilization of CPG on antimicrobial. Results: A total of 815 physicians were included in this study. About 80% of the surveyed physicians reported their adherence to the CPG on antimicrobial. Dimensions of "subjective norm", "perceived risk" and "behavioral intention" from the domain of physician belief, a dimension of "ease of use" from the domain of CPG traits, and dimensions of "top management support" and "organization & implementation" from the domain of hospital practice were significantly associated with physicians' utilization of CPG on antimicrobial. And except for working department, most demographics characteristics of the physician were not found to be significantly related to the CPG use. In addition, it also showed that region is a significant factor affecting physicians' CPG use. Conclusions: This study depicted the current status of CPG on antimicrobial and comprehensively identified its potential determinants not only from the three domains at the individual level, such as physician belief, but also from the location region at the organizational level. The results will provide a direct reference for the implementation of CPG on antimicrobial.