This study presents analysis of new multi-band light curves of beta Lyrae-type eclipsing binary SX Aur. Radial velocities of both components of the system were collected from the literature and simultaneous light curve solutions made to determine the properties of the system and absolute elements of its components. The derived masses and radii of the components are M-1 = 11.3 +/- 0.2 M-circle dot, M-2 = 6.9 +/- 0.1 R-1 = 5.32 +/- 0.02 R-circle dot and R-2 = 4.23 +/- 0.03.R-circle dot, while the distance of the system is estimated at 1220 +/- 75 pc. It was found that SX Aur is a shallow-contact binary and thus may be in the stage between beta Lyrae and W UMa-type binaries. From O-C based period analysis of SX Aur, it is seen that the period of the system increases at a rate of 0.0055 s yr(-1). The most plausible physical mechanism for this period variation is non-conservative mass transfer from the secondary to the primary component at a rate of 3.13 x 10(-7) M-circle dot yr(-1). (c) 2014 Elsevier B.V. All rights reserved.