We collected the data of the casualties by the Yiliang MS5． 7 and MS5． 6 earthquakes on September 7，2012 to analyze the characteristics and the causes of the earthquake-caused death． We found that in the earthquake-stricken area，the earthquake death toll was high but irregularly-distributed． The earthquake death toll of strong laborers was high． All of the victims were from the countryside，and the outlander victim were more than the local ones． The male victims were more than the female and accounted for a relatively-higher death rate． The Han victims were predominant，but the ones from other ethnic groups accounted for a relatively-higher death rate． The following factors such as the serious secondary geological disasters，poor aseismic performance of buildings，high population density，accumulation of earthquake damages and low level of economic development resulted in the heavy casualties． Mountain landslide caused by the two earthquakes directly caused the casualties． The casualties caused by mountain landslide exceed 74． 07% of the host population． Dense mining sites，raw mining method，miners’poor safety-awareness，and weak ability to escape from the unexpected incidents were the special causes． The causes we found can be helpful for the earthquake disaster reduction and the economic and social development in the rural areas in China．