This research was conducted as part of the National Technology Support Project 'Research on the cleaning of harmful surface residues in the stone grotto' , and is prepared as a draft of ' Standard chemical cleaning procedures to clean surface pollution on immovable stone relics'. In order to get an extensive and in - depth understanding of the subject, the experiences with laboratory chemical cleaning and on - site chemical cleaning at Yungang grotto is discussed. International chemical cleaning technique requirements and processes were reviewed. Also included were preliminary field investigations, criteria for selection of cleaners, glue and attachment techniques, evaluation of results, laboratory research and on - site tests. Positive and negative factors related to the chemical cleaning of stone relics are discussed. This work, therefore, provides useful information for the development of standards for chemical cleaning of stone relics.