Abstract: Effects of solid solution treatment on microstructures and properties of extruded AZ63A alloy were studied for improving the mechanical properties.Through enhancing the temperature and time of the solution treatment process.The conclusion that on one hand more second phases are dissolved and the plasticity of the sample is improved,but on the other hand the mechanical property is reduced because of the overgrowth of crystalline grains.Finally the extensibility of extruded magnesium alloy can be obviously improved when the tensile strength was fixed by solid solution treatment at 385℃ for twelve hours.