We designed the primers based on the sequence of the follistatin-related protein from Haemaphysalis longicornis Okayama strain accessed in GenBank. We cloned a gene encoding follistatin-related protein by RT-PCR, and the length cDNA is 814 bp, encoding a deduced protein of 289 amino acids. The alignment with the sequence of follistatin-related protein from the H. longicornis Okayama strain showed that the percent of nucleotide sequence and amino acid sequence is 97.8% and 99%, respectively. The expected size of GST-fused recombinant protein was 57 kD. We purified the recombinant protein through MagneGST protein purification system. Western blotting revealed that stronger reaction happened with the antiserum against eggs, but not clear with antisera against other developmental stages.