Mainly provided is a technique for directly identifying the genotype at locus Rf17 based on the specific base sequence data thereof. Also provided is a technique for artificially constructing a fertility-restored line. A method of restoring the fertility of CW-type cytoplasmic male sterile rice by inhibiting or reducing the expression of a gene comprising the base sequence represented by SEQ ID NO:2 in the above-described rice, and a method for determining the presence or absence of gene Rf17, which is a fertility restorer gene for CW-type cytoplasmic male sterility, comprising identifying a single nucleotide polymorphism (SNP) in the base at the 1812 position of the base sequence represented by SEQ ID NO:1 in the rice to be examined.