With the study of Quaternary debris flow activity cycle and its relationship with the environment evolution, we could predict the development laws and trends of modern debris. Based on typical debris flow deposition profile selected on various terraces in Bailong river basin,the occurrence of debris flow activity in years was determined with sediments dating data,and the relationships were compared and analyzed with Neotectonics history and deep - sea oxygen isotope delta~(18)O curve and loess - paleosol series. Studies shown that the debris flow activity in Bailong river basin could be divided into eight activity cycle,namely 1.5Ma,0. 73Ma,0. 565 ~ 0.425 Ma,0.245 ~ 0.165Ma,116.8 9.9Ka,50 ~ 25Ka,5 ~ 4Ka and since 3Ka. Debris flow deposition activity cycle had conjugated in time with the Neotectonics active period and had a good relationship with Odd segment of deep - sea oxygen isotope delta~(18)O curve and paleosol series of Luochuan loess - paleosol series. Debris flow activity was the result of tectonic movement coupled with climate change effects.