To study characteristics of the disintegration of purple parent rocks of the Matoushan group (K_2m), the Lufeng group (J_1l) and the Tuodian group (J_3t) as affected by water environment (soaking in water or wetting the surface), heat environment (natural diurnal temperature difference or extreme temperature difference), and their interaction, an experiment, designed to have five treatments, i.e. wetting and extreme temperature difference (WETD), socking and extreme temperature difference (SETD), soaking and natural diurnal temperature difference (SNTD), wetting and natural temperature difference(WNTD) and extreme temperature difference (ETD), were carried out. Results show that the five treatments followed the order of WETD > SETD > SNTD > WNTD and ETD in terms of rock integration rate, which suggests that in the case of big temperature difference, the parent rocks are more likely to disintegrate when getting wet and dry alternately than when being soaked all the time, while in the case of small temperature difference, it is the other way round. The factor of temperature alone does not have much effect on disintegration of the parent rocks. In terms of mean disintegration rate, the 3 parent rocks follow the order of J_3t﹥J_1l﹥K_2m, which is closely related to their chemical constitution, mineral compositions and microstructures. The experiment shows that disintegration rate has a good positive linear relationship with temperature variation, moisture alteration and/or number of treatment cycles in all the rocks except for J_3t, of which the integration rate is negatively correlated with the number of treatment cycles.