The recombinant plasmid PGC was constructed for transcription unit of c-myc gene with bi-direction in vitro, to make RNA probes for detection of c-myc mRNA and antisense RNA expression of transfectant HLR60-9, which was obtained from HL60 cells transfected with inducible c-myc antisense RNA expression plasmid. The results from HLR60-9 cells induced by Cd2+ indicated that expression of c-myc antisense RNA increased with Cd2+ concentration and exposure time, while c-myc mRNA expression progressively reduced. Using immunohistochemical technique no c-myc P62 protein expression was detected. The incorporation of 3H-TdR,3H-UR,3H-Leu revealed significant suppression of DNA, RNA and protein biosyntheses. It is suggested that the reversion changes previously reported in malignant phenotypes of HLR60-9 cells and the inhibition of macromolecule biosynthesis mentioned above were associated with the blockade of c-myc gene expression by its antisense RNA.