Objective: To construct RACE cDNA library of Hydra magnipapillata.Methods: Total RNA was isolated from Hydra magnipapillata,and purified mRNA from total RNA was used to construct RACE cDNA library with the SMART cDNA library con-struction kit.In order to identify the cDNA library,the polymerase chain reaction(PCR) primers for 5' RACE,3' RACE and the full-length cDNAs of actin gene were designed based on the pupative cDNA sequence of actin from GenBank.Results: Agarose gel elec-trophoresis showed that the lengths of full-length cDNAs in this library were pooled mainly between 500 and 2 000 base pairs.By RACE PCR,amplified products were obtained with all the gene-specific primers and adaptor primers.Conclusion: The quality of the RACE cD-NA library was high and appropriate for cloning the full-length cDNAs of functional genes in Hydra magnipapillata.