Sn-Pb solder alloys, widely used in electronic industry, will be restricted because of the toxicity of Pb. That is paramount importance that developing viable alternative lead-free solders for electronic assemblies. Sn-Ag-Cu alloys are better alternative because of its good performance. But they have a melting temperature of 217-225 degrees C that is much higher than that of Sn-Pb eutectic alloy, 183 degrees C. It may be very difficulty to realize industrialization. Sn-Ag-Cu-Ga solder alloys have been studied in this paper, including a series of properties tests, such as melting point, hardness, shear strength and solderability. The best composition of Sn-Ag-Cu-Ga lead-free solder alloy has been obtained.