AIM: To construct a subtracted cDNA library of differentially expressed genes in human unstable angina lymphocytes. METHODS: Suppression subtractive hybridizations (SSH) were performed between the patients with unstable angina pectoris and stable angina pectoris. Lymphocyte RNA, the obtained forward and reverse cDNA fragments were directly inserted into T/A cloning vector and transformed into E.coli JM 109 to construct a subtractive cDNA library. The inserting fragments were screened by blue and while blot screening and bacterium liqulid PCR. RESULTS: Each subtractive cDNA library contained more than 2000 positive bacteria clones. Most of them distributed between 200-600 bp inserts. CONCLUSION: The library is efficient and lays solid foundation for screening and cloning new and specific expressed genes in unstable angina lymphocyte RNA.