Goos-Hänchen shifts are investigated when total reflection occurs at the interfaces associated with single-negative materials (SNMs). A general rule for judging the direction of the Goos-Hänchen lateral shift concerning lossless media is obtained: Whether the lateral shift is positive or negative depends on the sign of micro1micro2 for TE-polarized incident beams and epsilon1epsilon2 for TM-polarized incident beams. It was theoretically demonstrated that, at the interface associated with SNMs, TE- and TM-polarized incident beams experience opposite Goos-Hänchen lateral shifts. An effective and simple approach to discriminating epsilon-negative material and micro-negative material is proposed.