The disclosure provides a use of a fluorescent saccharide-based derivative in cell detection. The fluorescent saccharide-based derivative is obtained from a reactive material through an imine formation reaction, and the reactive material is selected from a composition (A) or a composition (B). The composition (A) includes a reducing sugar compound and an amino group-containing compound having at least one primary amino group. The composition (B) includes an amino sugar compound and a carbonyl group-containing compound, and the amino sugar compound contains at least one primary amino group.