Abstract: Total RNA was isolated from millet (Setaria italica Beauv.) seedlings. Degenerate primers of actins' coding region were designed and 5'RACE technique was employed to obtain the actin cDNA of Setaria italica. Southern blotting analysis with probe from pea tendril actin gene coding region shows that there is a high similarity between the actin of　Setaria italica and pea. The putative actin gene was sequenced after cloning into pGEM_T vector and sequencing result revealed that it contains an open reading frame of 1131 bp, encoding a protein of 377 amino acids. Similarity comparison with other actin gene sequences in the GenBank shows that it shares over 60% nucleotide sequence similarity and over 89% amino acid sequence similarity with other actins. The hylogenetic tree reconstructed on the base of amino acid sequences suggests that the relationship between millet actin and rice actins(RAc2, RAc3) is most intimate and they might have diverged at the same time.