An object of the present invention is to provide a blood test kit of which a component in a small volume of blood can be mailed in a safe state by controlling the influence of the outside temperature during the mailing, and a highly accurate blood analysis method in which coefficient of variation of a measurement value is reduced. According to the present invention, a blood test kit including a diluent solution for diluting a blood sample； a separating means for recovering blood plasma components from the diluted blood sample； a container for storing the blood plasma components recovered from the diluted blood sample； and a cold insulation means for cold-insulating the container, is provided.
