Objective To find out the common syndrome factors of chronic obstructive pulmonary disease（COPD） at stable stage by applying latent structure method.Methods The symptom information were collected from the patients with COPD at stable stage by using a unified collection table of clinical information

and then a database was established

in which the data were imputed and retreated.All data were analysed with latent structure method

and the constructed latent structure model of COPD was interpreted based on professional knowledge of Chinese Medicine.Results There were totally 30 latent variables and 70 latent categories in the latent structure model of COPD at stable stage.After the interpretation with professional knowledge

there were 23 significant latent categories obtained.The syndrome factors related to diseases locations of COPD at stable stage included lung

spleen

kidney

stomach and heart.The syndrome factors related to disease nature included yin deficiency

yang deficiency

qi deficiency

phlegm（dampness）

blood stasis

qi stagnation and heat.Conclusion The results of analysis on the prospective non-supervising data of COPD at stable stage indicate that the modeling by latent structure method is similar to TCM theory

and have a higher objective compared with the analysis on supervising data.The research has given some supports for working out the diagnostic standard of COPD at stable stage.