Abstract: On the bases of experimental measurement and tests and theoretical calculation,the supersymmetry companions of present neutrinos,neutralinos Ue,B0(q2,g),are proved to be the best candidate particles of dark matter in the universe,and the energy released by supernova explosion is thought to make the temperature T and the pressure p of the thermal equilibrium state of universe background photons go up.If pressure is compared to "anti-gravitation",when "anti-gravitation"(pressure) is bigger than gravitation,the universe will expand,and when "anti-gravitation" is smaller than gravitation,the universe will contract.