The scintillation indices (SIs) of Gaussian beams and vortex beams propagating in turbulent atmosphere are investigated experimentally. It is shown that with the increase of propagation distance, the SI of Gaussian beam around optical axis increases gradually, but the SI of vortex beam with topological charge of 4 increases, achieves the maximum value at a fixed distance, and then decreases as the continued increase of propagation distance. The SI of vortex beam can be smaller than that of Gaussian beam under certain conditions.