Abstract: Objective To understand the maternal mortality and its influence factors in a Tibetan population in Gansu province and to provide information for the decrease of maternal mortality.Methods The retro spective study method was used to analyze the causes and the related factors of mate rnalmortality in the autonomous prefecture from 2000 to 2008.Results The maternal mortality rate in the population decreased from 224.54/100 000 in 2000 to 74.75/100 000 in 2008,with an significant decreasing trend(χ²=5.077,P=0.024).The leading cause of death in pregnant women was obstetrichem orrhage.With the increasing of hospital deliveries,the maternal mortality rate decreased(F=17.478,P=0.004).Conclusion The maternal mortality rate of Gannan Tibetan autonomous prefecture was gradually decreased,but it was still higher than the average maternal mortality rate of Gansu province in the same period.