This study aimed to assess the diagnostic potential of four recombinant cysteine proteases (r<i>Cs</i>CP1-4) for human clonorchiasis.<h4>Methods</h4>An indirect ELISA was developed to measure serum reactivity (IgG, IgG subclasses, IgA) against r<i>Cs</i>CP1-4. The gene discussed is CTSB; the disease is clonorchiasis.