PURPOSE: To perform the quantitative determination of hydroxyl group and amino group with high accuracy and good reproducibility by using a specific derivation reagent for quantitatively determining hydroxyl group and amino group.

CONSTITUTION: The derivation reagent for the quantitative determination of hydroxyl group and amino group is used as ultraviolet(UV) labelling agent of a UV labelling method and represented by the formula (wherein R1 is a 1 to 20C divalent or trivalent hydrocarbon group which may have oxygen atom, nitrogen atom, sulfur atom or silicon atom as the coupling group, each of R2 and R3 is hydrogen atoms, a halogen atom, nitro group, sulfonic group and a salt thereof, a 1 to 20C hydrocarbon group, an alkoxy group, a ketone group, an ester group, aldehyde group or carboxyl group and a salt thereof, m is an integer of 1 to 3 and n is an integer of 1 to 4). A hydroxyl group or amino group in an org. compd. can be quantitatively determined with high accuracy by the use of the above mentioned reagent.