A M_S5.8 earthquake occurred in Yongdeng county of Gansu Province on July 22,1995. It caused buildings to get damaged,property to get lost and personnel to get wounded or to die. Immediately after this event,scientific investigation and earthquake disaster assessment groups are sent to the earthquake area.According to the principle and method in The Working Guidebook of Earthquake Disaster Investigation and Loss Assessment and based on the survey of general situation,natural environment,social economy,pillar estate,population and buildings,we investigated the samples of building destruction and loss of property in areas of intensity Ⅷ,Ⅶ,Ⅵ,Ⅴ.According to the earthquake disaster assessment software EDEP 93,the data base is set up.Results of scientific and reasonable earthquake disaster loss assessment are provided.The characteristics of earthquake area are analysed and the earthquake disaster distribution characteristics are also researched.Last,the experiences and lessons of protection against earthquake and disaster reduction are summed up.