Loneliness is a common psychological experience in older adults, which may result in severe negative health outcomes. This paper aims at investigating the causal relationship between the Internet use and the perception of loneliness of older-adult population. First,   the hypothesized relationships on the basis of a brief literature review is established, and then  an econometric model is proposed. To test the hypotheses, the cross-sectional data of China Health and Retirement Longitudinal Study（CHARLS）is employed. An Ordinary Least Square regression with robust standard error is conducted to estimate the coefficients. To ensure the robustness of the regression results, this paper follows a robustness check by using the counter-factual design and propensity score matching. The results show that the Internet use behavior is negatively associated with the perception of loneliness among older adults, suggesting that Internet use plays a mitigating effect on older adult's loneliness perception. Drawn on empirical results, several practical implications, including the motivation, ability, and user experience design of older adult's Internet use, are discussed to shed light on the Internet adoption and loneliness alleviation among older adults.