[Objective] The primary factors which are responsible for poverty in ecologically sensitive areas were studied in order to provide a theoretical basis for implementing anti-poverty measures.[Methods] This study selected an eco-clean watershed as the research target, which was located at Jiaying in the He'nan Province. In particular it was situated in the area of the water source of the Middle Route Project of South to North Water Diversion. The gray correlation model based on the entropy weight was employed to calculate the correlation degree between the poverty rate and the influencing factors in the small watershed; further, the primary factors affecting the poverty rate in the small watershed were analyzed.[Results] ①The poverty rate in Jiaying eco-clean watershed was 5.69% in 2017, which was regarded as 2.21 times higher than that of the average in the He'nan Province at the same period. ②The average poverty rate in the middle reaches of small basins was 7.13%, which was significantly higher than that in the upper (6.26%) and the lower reaches (5.65%). ③Various factors were observed to affect the poverty in small watersheds, namely:the amount of cultivated land per capita, proportion of the labor force in the total population, annual household dietary expenditures, proportion of junior middle schools, household annual average wage incomes, ground slope, and annual average medical expenditures of households. ④However, the primary factors affecting the poverty of each village in the small watershed were different, exhibiting regional differentiation.[Conclusion] The key to solve the problem of poverty in small watersheds is to take measures to alleviate the poverty according to the local specific conditions, and by rendering the complete use of the surplus labor force and the surplus working time. Further, an increase in the investment with regard to education is necessitated with appropriate solutions for tackling poverty caused by disability and disease.