Cohort studies in North America and western Europe have reported increased risk of mortality associated with long-term exposure to fine particles (PM ), but to date, no such studies have been reported in China, where higher levels of exposure are experienced. We estimated the association between long-term exposure to PM with nonaccidental and cause-specific mortality in a cohort of Chinese men. We conducted a prospective cohort study of 189,793 men 40 y old or older during 1990-91 from 45 areas in China. Annual average PM levels for the years 1990, 1995, 2000, and 2005 were estimated for each cohort location using a combination of satellite-based estimates, chemical transport model simulations, and ground-level measurements developed for the Global Burden of Disease (GBD) 2013 study. A Cox proportional hazards regression model was used to estimate hazard ratios (HR) for nonaccidental cardiovascular disease (CVD), chronic obstructive pulmonary disease (COPD), and lung-cancer mortality. We also assessed the shape of the concentration-response relationship and compared the risk estimates with those predicted by Integrated Exposure-Response (IER) function, which incorporated estimates of mortality risk from previous cohort studies in western Europe and North America. The mean level of PM exposure during 2000-2005 was 43.7 μg/m (ranging from 4.2 to 83.8 μg/m ). Mortality HRs (95% CI) per 10-μg/m increase in PM were 1.09 (1.08, 1.09) for nonaccidental causes; 1.09 (1.08, 1.10) for CVD, 1.12 (1.10, 1.13) for COPD; and 1.12 (1.07, 1.14) for lung cancer. The HR estimate from our cohort was consistently higher than IER predictions. Long-term exposure to PM was associated with nonaccidental, CVD, lung cancer, and COPD mortality in China. The IER estimator may underestimate the excess relative risk of cause-specific mortality due to long-term exposure to PM over the exposure range experienced in China and other low- and middle-income countries. https://doi.org/10.1289/EHP1673.