The disturbance of tourism on the species diversity in different layers of the Pinus taiwanensis communities in Tianzhu Mountain National Forest Park were studied by using species richness index (S), Simpson index (D), Shannon-Wiener index (H), and Pielou Evenness index (J). The highest diversity index values were found for arbor layer under the low disturbance. The highest diversity index values were found for other layers under the intermediate disturbance. The values of S, D, H and J under the low disturbance were 38, 3.0976, 0.9326, and 0.7515, respectively． The values of these indices under the intermediate disturbance were 44, 3.2519, 0.9421, and 0.8594, respectively, higher than those under the low disturbance, especially for the shrub and herb layers. Under the high disturbance, the values of these diversity indices were 34, 3.0095, 0.9289, and 0.7834, respectively, lower than those under the intermediate disturbance. The stability of forests under different disturbances was examined with the community dominance index (C). The C value under the intermediate disturbance was the lowest among the three disturbances. This suggests that the intermediate disturbance can increase species diversity but decrease community stability.