The present invention provides galectin-9 variant having substantially the same bioactivity as in wild-type galectin-9 and being superior in protease stability, solubility, and yield. The galectin-9 variant according to the present invention is a protein including the following NCRD and the following CCRD composed of an N-terminal region and a C-terminal region. The C terminus of the NCRD and the N terminus of the CCRD are directly or indirectly bound to each other. The NCRD is (N1) a peptide composed of an amino acid sequence represented by SEQ ID NO: 1. The N-terminal region of the CCRD is (C-N1) a peptide composed of an amino acid sequence obtained by deletion of 1 to 17 amino acids in an amino acid sequence represented by SEQ ID NO: 3. The C-terminal region is (C-C1) a peptide composed of an amino acid sequence represented by SEQ ID NO: 5.
