<p><strong>Abstract.</strong> Volunteered Geographic Information (VGI) crowdsourced from volunteering posts, is closely related to contributors’ mapping behavior. As the most noticeable VGI source, OpenStreetMap (OSM) is one of the most studied objectives in VGI and data contributors. In this paper, temporal-spatial analysis is applied in seeking the temporal and spatial patterns of the number of buildings and contributors in Beijing, China. Temporal changes of the number of updated buildings, and the population of total, new and quitted contributors, were interpreted, as well as the spatial distribution of updated buildings, participated contributors, and frequency of updates. The result suggests that the number of updated buildings, participated contributors, new and quitted contributors are growing. Buildings are mostly updated by a small number of contributors, the majority of which did not participated in mapping in the previous year. Most contributors update buildings for one year without succeeding till the next. Contributors are interested in updating a large amount of buildings frequently around landmarks, commercial districts, universities, and transit hubs. They update buildings at an expanding range and an increasing density, but their attentions do not necessarily bring large quantity of building updates. In general, OSM buildings in developing regions with less complete database are updated under similar patterns as developed regions where data are much more complete.</p>