In this study,a cDNA fragment of chicken IL-2 about 439 bp was cloned from ConA- stimulated chicken spleen cells by reverse transcription (RT)-PCR with a pair of designed primers. Then it was inserted into pcDNA3, an eukaryotic expression plasmid by a directional link, identified by endonuclease and DNA sequencing, which conformed to chicken IL-2 gene fragment reported in the literature. This fragment was further inserted into a prokaryotic expressive plasmid pGEX-4T-1, and then it was transferred into the strain BL21. After the bacteria were induced and cultured, expressed protein was separated. A band with 42 000 of molecular weight was observed on SDS-PAGE. All these results suggest that the cloned gene of chicken IL-2 is expressed in prokaryotic cells.