We investigate the impacts of population aging on bank lending using micro-level data from the Chinese banking industry. We find that an aging population significantly reduces the volume of bank lending. The underlying mechanism driving this trend comes from a reduction in bank deposits and a decline in banks' risk-taking. At the same time, population aging induces a structural change in banks' loan portfolios. Banks are strategically reducing the share of their loan portfolios exposed to the greater risks associated with an aging population; additionally, they utilize cross-regional operations to lessen the adverse effects of aging. The contractionary effect of population aging on bank lending is more pronounced for non-state banks and banks in highly competitive markets. These findings highlight the importance of considering population aging in assessing both the aggregate volume and the structural composition of bank loans.