Urban-geographical research using location-based social media (LBSM) has itself been characterized by uneven geographies in that most studies deal with Europe and North America. This implies a relative dearth of studies focusing on countries such as China, and this in spite of the country having the largest number of Internet users in the world. This paper proposes to address this lacuna by showing the research potential of LBSM services associated with Weibo, by far the most popular online social microblog-ging and networking service in China. To this end, we map inter-city connections within the Yangtze River Delta based on three million individuals’ space-time footprints derived from Weibo. Empirical results reveal that the inter-city connections derived from Weibo present both common and speciﬁc spatial patterns associated with inter-city travel. We ﬁnd that a small percentage of cities and city-dyads constitute the backbone of this inter-city network. The dominant direction of individual ﬂows tends to be from primary cities to sub-primary cities, and from peripheral cities to primary cities. In addition, city-dyad connectivities do not strictly follow cities’ positions in terms of their centralities in the hierarchical distribution. Furthermore, the effects of administrative boundaries and cities’ administrative level are signiﬁcant. We benchmark these insights by re-examining our ﬁndings against the backdrop of polycentric developments in the Yangtze River Delta, which conﬁrms the potential usefulness of LBSM data for analyzing urban-geographical patterns.