The negative Goos-Hänchen shift (GHS) on a two-dimensional photonic crystal with an effective negative refractive index is investigated by simulation and experiment. The measured refractive index of the fabricated photonic crystal is nearly -0.44. The difference between the Goos-Hänchen shift of the transverse electric wave GTE and that of the transverse magnetic wave GTM (DGHS) in the height direction of a silicon rod is measured at three incident angles. The result shows that DGHS is always smaller than -GTM, thus GTE<0; therefore, the negative GHS does occur on the surface of the photonic crystal with a negative refractive index.