An object of the present invention is to provide a kit and a method capable of achieving high-precision measurement of a measurement target substance in a biological sample in a wide concentration range from a low concentration to a high concentration. According to the present invention, there is provided a kit for measuring a measurement target substance in a biological sample, the kit including: a labeled particle having a first binding substance capable of binding to the measurement target substance in a biological sample and having a first blocking agent; and a substrate having a second binding substance capable of binding to any one of the measurement target substance or the first binding substance and having a second blocking agent, in which the labeled particle is a luminescent labeled particle containing at least one kind of compound represented by Formula (1) and a particle, and the first blocking agent and the second blocking agent are different from each other.




Each symbol in Formula (1) has the meaning described in the present specification.