Label free LC-MS/MS method was used in seeking of unstable angina blood stasis syndrome(UABSS) differentially expressed plasma proteins. A polyclonal antibody affinity column, nanoAcquity UPLC and Synapt HDMS were used on plasma of two classes of samples(12 UABSS patients and 12 health volunteers). The results show that the method has a good reproducibility. The ionic strength coefficient of variability was less than 5%, retention time coefficient of variability was less than 3%. 3843 proteins were detected, among which 24 kinds of proteins differentially expressed large than 1.5 fold, include 11 down-regulated and 13 up-regulated(include 3 kinds of proteins only found in UABSS patients). The dynamic range was about 104. ACTA1, ITIH3 and LBP were only found in the plasma of UABSS patients, Haptoglobin, SAA, CP, C6, MYH11, APOH and ANXA6 were significantly highly expressed in the plasma of UABSS patients, while HBB, HBA, HBE, HBD, HBG, HRG, IGHG, GSN and TF were lowly expressed in the plasma of UABSS patients. These identified increased expressed proteins could be divided into four categories according to their functions: (1) acute phase reactive protein; (2) complement protein; (3) cytoskeletal protein; (4) blood coagulation protein. The decreased expressed proteins could be divided into five categories: (1) apolipoprotein; (2) transport protein; (3) anticoagulated blood protein; (4) immunoglobulin; (5) cytoskeletal modulin protein. In conclusion, UABSS may correlated with inflammatory reaction, lipid metabolic disorder, myocardial damage, blood coagulation factor abnormal, oxygen transport obstacle, and these differentially expressed proteins could provide clues for the study and discovery of new protein targets for antianginal drugs. The label free proteomics is an efficient method for the discovery of differentially expressed proteins of complicated sample.