<p>This study aims to precisely identify the tensile stress–strain relation of a Sn-3.0Ag-0.5Cu (SAC305) solder using the digital image correlation (DIC) method. Uniaxial tensile tests are generally carried out to obtain stress–strain curves with dog-bone-type specimens. Strain data during the tests are measured using sensing systems such as mechanical extensometer, visual extensometer, and strain gauge. Because it is difficult to confirm the strain distribution in the specimen with these sensing systems, the digital image correlation system has recently been increasingly used for obtaining displacement and strain data in tension tests. SAC305 usually shows nonuniform deformation during tensile tests, unlike conventional metal alloys, although the gauge section is designed to be uniformly deformed following a standard procedure for tensile tests. Therefore, it is necessary to develop a method for the identification of tensile properties when the deformation in tension is nonuniform. In this study, tensile tests with the DIC system were conducted to obtain stress–strain curves of the SAC305 under different loading speeds. The strain distribution was analyzed in terms of variation in strain rate and strain path. An identification method was then proposed by collecting valid stress data according to the strain and their fit using a material hardening model. Based on the proposed method, the stress–strain curves can be acquired up to a larger strain region than with the conventional method. This will be useful for obtaining material properties for simulation of packaging reliability for electronic devices.</p>