The authors advocate a program for diagnosing Liver-Qi Deficiency Syndrome (LQDS) based on the TCM theory and clinical practice. Through investigation, LQDS was found to be widely existed as latent period or as external manifestation, which occupied 18.85% in Qi Deficiency Syndrome. The subjects were divided into four groups including normal group, Spleen-Qi Deficiency Syndrome (SQDS) group, LQDS with Liver diseases (LD) and LQDS with non-Liver diseases (NLD) group. In order to explore the essence, the simultaneous determinations were done on lactate dehydrogenase (LDH) and its isoenzyme, dopamine beta-hydroxylase (D beta H), trace element Zn and Cu, and other serological indexes such as GPT, TP, Alb, A/G, etc. The results were, the content of LDH and trace element Zn in both LQDS-NLD and SQDS were significantly lower than that of normal group. D beta H reflecting sympathetic nerve function in LQDS-NLD was significantly higher than that of both normal and SQDS group; comparing LQDS-LD and LQDS-NLD group, the content of GPT, LDH, LDH5 and trace element Cu in former was significantly higher than that of the latter, but the content of TP, Alb, A/G, D beta H and Zn in former was remarkably lower than that of the latter. In order to avoid confusion, in studying this syndrome, one should distinguish LD and NLD.