Abstract: Based on the published nucleotide sequence of MIC5 gene of Eimeria tenella, a pair of primers was designed. The EnMIC5 gene was amplified by PCR from the genomic DNA of E. necatrix. The amplicons were cloned into pMD18-T simple. Sequence analysis showed that the PCR fragment of EnMIC-5 gene is 1 470 base pairs in length and encodes a partial protein of 490 amino acids. Then the gene was introduced into pET-28a(+) vector, and the recombinant plasmid pET-EnMIC-5 was expressed in the E. coli BL21. The results of SDSPAGE revealed that the fusion protein with molecular weight about 57-5 ku was over-expressed after induction of IPTG. Western-blot results demonstrated that the expressed recombinant protein was reacted with sera of chickens against E. necatrix infection. A high titer of antibody was detected at two weeks after the injection of the recombinant protein in Kunming mice suggesting that it should have good immunogenicity, and make mice produce high level of specific antibody.