A chemically synthesized alpha-hANP gene was inserted into plasmid YFD18, which was an expression-secretion vector of yeast. The recombinant then transformed in the yeast Y33. The expression level of yeast transformants was about 700 micrograms ANP/L detected by RIA. More than 99% of expression products were secreted in the culture medium. N-terminal analysis of purified product showed that the first 4 amino acid residues of alpha-hANP were deleted.