When antisense myc oligodeoxynucleotide (ODNs) (18-mer) were introduced into the medium of the smooth muscle cells (SMCs) of WKY in concentrations ranging from 6 to 12 uM,the 18-met ODNs,in a concentration-related manner,decreased SMCs growth induced by endothelin (10~(-7)mol/L). The inhibitory effect (12umol/L) was about 43% in 12h, 33% in 24h and 27% in 36h. Sense ODNs had little effect. Meanwhile, the anti c-myc had inhibitory effect on production of Myc protein of the SMCs. Our results demonstrate that an antisense ODNs directed at the messenger RNA of myc decreases the expression of myc gone product and reduces SMCs proliferation induced by endothelin.