One significant criterion for approving urban renewal business is more than half old buildings in a renewal unit, which refers to any division within the renewal area implemented as an individual urban renewal business. However, the physical building life of reinforced concrete buildings is announced 60 or 50 years by public authorities. Local governments normally give incentives for enhancing the implementation of urban renewal business and lead to buildings are untimely demolition especially in the renewal units which are applied by landowners and out of designated urban renewal areas. In order to review the urban renewal business are implemented to rehabilitate the worn-out or obsolescent parts of a town, an aim of this paper is to clarify the impacts of premature building demolition on the implementation of urban renewal business. The approval renewal unit applications and the data of the construction and demolition permits are employed for the analysis.