Background and Aims: Elders have been considered being vulnerable to air pollution, including particulate matters (PM). However, relatively scant attention has been paid for the long-term PM effect on the elder’s lung function parameters, especially in Asian population. The study aims to evaluate the association and the potential source related effect of exposure to ambient air pollutants and lung function change in general elders in Taiwan. Methods: We conducted an elderly cohort study from October 2015 to December 2017. Subjects were enrolled from five hospitals of variant background PM concentrations. Elders aged 65 and didn’t have cancer and communication problems were invited to participate in this study. Forced lung function was measured annually by uniform machines in the five hospitals. Long-term (2016 annual mean concentration) exposure to air pollution was estimated by Kriging method at the residential address of each subject. Principle component analysis with varimax rotation was done for six criterial air pollutants to describe the potential sources (factors) and extract the factor scores. We assessed the association between exposures and 1-year lung function change by linear regression modelling with adjustment of demographics, baseline lung function and copollutants. Results: 861 subjects with mean age of 70.3 year old completed baseline and 1-year follow-up lung function studies. After adjustment for confounding factors, per 1 ug/m3 increase of fine particulates were significantly associated with 1-year decline of FVC (−18.23 mL, −0.75%, P < 0.0001) and FEV1 (−15.23 mL, −0.8%, P < 0.0001). Factor analysis identified stationary fossil fuel combustion- (PM & sulfur dioxide) and traffic- related (nitric dioxide & carbon monoxide) sources of air pollution. The former was associated with lung function decline. Conclusion: Long-term exposure to ambient fine particulates and stationary fossil fuel combustion-related air pollution were associated with 1-year lung function decline among the elders in Taiwan.