Undoubtedly, the main purpose of building fire protection is to ensure life safety and to reduce financial fire losses. If we can examine the affecting factors those contribute fire risks from real fire cases and pro pose good solutions, then fire research could move steps ahead and the life losses and property losses could be reduced largely. This study focuses on the investigations from real cases of residential building fires from January 1999 to February 2001 at Taipei city, Hsiu-Ju county, Taichung city, Tainan city and Tainan county. Contexts of investigations examine primarily on building safety characteristics regarding types of building constructions, fire escape conditions, fire-fighting situation, installations and maintenances of fire protection systems and the resulting life losses and financial losses. These affecting factors are measured and examined by questionnaire survey as well as official reports. Factors development and test of significant difference between variable or factors have been done by employing statistical methods such as factor analysis, Chi-square test, t-test and analysis of variance. Attempts are made both to find affecting factors for life losses and financial losses in building fires and to provide some strategies and plans for the brigade and the public in fire prevention activities.