An object of the present invention is to provide a kit and a method which are capable of measuring a measurement target substance in a biological sample with high precision in a measurement range from a low concentration range to a high concentration range. According to the present invention, there is provided a kit for measuring a measurement target substance in a biological sample, including a labeled particle having a first binding substance capable of binding to a measurement target substance in a biological sample, and a substrate having a second binding substance capable of binding to any one of the measurement target substance or the first binding substance, in which the labeled particle is a luminescent labeled particle containing at least one kind of compound represented by Formula (1) and a particle. Each symbol in Formula (1) has the meaning described in the present specification.