With the advance of wireless networks, location-based services have become very important as people often need to query for addresses of unfamiliar locations through Web and then locate the position on the map. Existing geographic information systems based on crowd-sourcing are insufficient and have a slow update progress. However, it can actually be complemented by automatically extracting addresses of location entities and associated information from general pages. Thus, effectively crawling webpages with addresses is a practical challenge for enriching the location entity database. This research is devoted to automatic address and associated information extraction to provide information retrieval on maps, i.e. integrating the process of location entity query on Web and positioning on maps. We build a geographic information system of location entities by crawling the Web via three strategies for Chinese addresses. One point two seven (1.27) million distinct Chinese addresses are crawled using 1.08 million HTTP requests, leading to a return-of-investment of 1.169.