Objective To summarize the disease

syndrome and symptom distributive characteristics of Yang deficiency syndrome based on literature. Methods The clinical research literature related to Chinese medicine Yang deficiency syndrome were reviewed in China National Knowledge Infrastructure（ CNKI） and VIP Data from January of2007 to June of 2014. Yang deficiency syndrome clinical literature information database was established. Name of diseases

syndrome types

syndrome essence and symptoms were standardized

and the frequency of each item was calculated. Results Totally 550 papers were included

with 111 Chinese medicine diseases and 168 western medicine diseases. Top 3 of high frequency Chinese medicine diseases were stomachache（ 39）

edema（ 38） and diarrhea（ 27）. Top 4 of high frequency western medicine diseases were chronic heart failure（ 34）

chronic gastritis（ 21）

coronary artery disease（ 18） and cirrhosis of liver（ 18）. Ther were 36 syndromes related to Yang deficiency syndrome. Top 3 of high frequency were Yang deficiency of spleen and kidney（ 149）

Yang deficiency of kidney（ 97）and Yang deficiency of spleen and stomach（ 82）. There were 7 kinds of disease location syndrome essence. Top 3 of high frequency were kidney（ 280）

spleen（ 240） and stomach（ 82）. There were 8 mixed disease character syndrome essence types. Top 3 of high frequency were water retention（ 34）

blood stasis（ 28） and cold（ 20）. There were 375 symptoms. Top 3 of high frequency were peripheral coldness（ 285）

fear of cold（ 272） and loose stool（ 189）. Conclusion The pathological status of Yang deficiency played an important role in chronic diseases and later period of diseases. Yang deficiency syndrome was widely distributed and mostly mixed excessive pathogens

such as water retention

blood stasis

cold-damp

phlegm-turbidity

Qi stagnation

etc.