To provide a method for determining a nucleic acid, capable of simplifying detection of an amplified substance of a nucleic acid and accurately carrying out determination.

This method for determining a nucleic acid comprises subjecting a nucleic acid specimen to amplification reaction of a nucleic acid in the presence of two kinds of primers complementary to both ends of a specific sequence domain required for amplification of the specific sequence domain of a target nucleic acid. Both 5' ends of the two kinds of the primers are bonded to a polymer carrier (e.g. carboxyl group-containing polystyrene latex). The amplification reaction of the nucleic acid is carried out by using the polymer carrier- bonded primers and the amplified amount of the nucleic acid is measured by the agglutination reaction of the polymer carrier.