Aim To study the apoptosis and the expressions of protooncogenes bcl-2, P53 and c-myc of the smooth muscle cells (SMC ) derived from rabbit atherosclerotic (As) plaques. Methods Cell apoptosis was in sute detected with the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and DNA agarose gel electrophoresis, respectively. Expressions of protooncogenes bcl-2, c-myc and P53 were observed by Northern blotting.Results It was found that a lot of SMC were positively stained with TUNEL in As plaque tissues. The DNA electropherosis of the plaque tissues showed a ladder pattern. Northern hybridization showed that expressions of protooncogenes bcl-2 and P53 in the plaque tissues were markedly increased, compared with the normal tissues, but the expression of c-myc was decreased. Conclusion Apoptosis of SMC existed in the As plaques. The expressions of protooncogenes bcl-2 - cmyc and P53 play a important role in regulating the apoptosis of SMC in the As plaques.