Laser ultrasonic technology, a noncontact nondestructive evaluation method, can be applied to evaluating the properties of human teeth. With a finite element method, this paper studies laser induced surface acoustic wave (LSAW) characteristics propagating in human teeth. Setting up a theory model for laser-introduced surface acoustic wave (SAW) propagating in human incisors, it discusses the temperature field induced by laser irradiate in dental surface, as well as the effects of inhomogeneous enamel and early dental caries (white spot lesion) on LSAWs. Studies in this letter can provide a theoretical basis for nondestructive evaluation of human teeth with laser ultrasonic technology.