When 137Cs and Sr- Y two radioactive sources are mixed, it will produce a mixture of β radioactivity. This paper is seeking a measurement and analysis means to obtain the two sources β radioactive intensity respectively in mixed state. First, we measure the ^137Cs and ^90Sr- ^90y source mixed β radioactive intensity, then use Fermi -Curie depicted method to analyze the mixed -measurement data of β spectroscopy. Fermi - Curie depicted can drawn the area of high and low energy region, thereafter by utilizing the integral sum on the number of ...