Conservators in museums should always consider the following questions: What is the ideal environment for objects? What factors should be considered for museum environment, and why? The research and management of museum environment have been focused on these two themes for long, which have helped to improve the condition of objects in museums. Nevertheless, the work has not been carried out thoroughly in museums due to various limitations. In these years, some conservators are focusing on the study of monitoring and control techniques for museum environment. The identification, monitoring, purification and control of pollutants in museums are the key questions for museum storage and display. The article consists of the research on museum environment including its contents, monitoring and control techniques and assessment methods by means of comparative study, and brings the concept of clean condition for objects, which tries to further improve the condition of objects in museums.