A spin-injection magnetic random access memory according to an embodiment of the invention includes a magnetoresistive element having a magnetic fixed layer whose magnetization direction is fixed, a magnetic recording layer whose magnetization direction can be changed by injecting spin-polarized electrons, and a tunnel barrier layer provided between the magnetic fixed layer and the magnetic recording layer, a bit line which passes spin-injection current through the magnetoresistive element, the spin-injection current being used for generation of the spin-polarized electrons, a writing word line through which assist current is passed, the assist current being used for the generation of an assist magnetic field in a magnetization easy-axis direction of the magnetoresistive element, and a driver/sinker which determines a direction of the spin-injection current and a direction of the assist current.