An object of the present invention is to provide a blood analysis method in which a high level of repeatability and reproducibility is achieved with respect to measurement values in a blood sample of 50 μL or less, and a blood test kit which is used for the blood analysis method. According to the present invention, a blood analysis method including a step of diluting a collected blood sample with a diluent solution； a step of determining a dilution factor by using a normal value of a normal component which is homeostatically present in the blood； and a step of analyzing a concentration of a target component in the blood sample, in which a volume of the blood sample is 50 μL or less, a dilution factor of blood plasma components in the blood sample is 14 or higher, and the diluent solution is a diluent solution which does not contain the normal component which is homeostatically present in the blood, is provided.
