A largely unexplored big data application in urban contexts is how cultural ties affect human mobility patterns. This article explores China's intercity human mobility patterns from social media data to contribute to our understanding of this question. Exposure to human mobility patterns is measured by big data computational strategy for identifying hundreds of millions of individuals' space–time footprint trajectories. Linguistic data are coded as a proxy for cultural ties from a unique geographically coded atlas of dialect distributions. We find that cultural ties are associated with human mobility flows between city pairs, contingent on commuting costs and geographical distances. Such effects are not distributed evenly over time and space, however. These findings present useful insights in support of the cultural mechanism that can account for the rise, decline, and dynamics of human mobility between regions.