From March,2014 to October 2015，Ebola outbreak disease of the Republic of Sierra Leone caused 8704 cumulative confirmed cases and 3589 deaths countrywide.Method:Clinical and demographic data were mainly collected with the standard case investigation forms from August 2014 to June 2015 in Freetown，Sierra Leone.It was supplemented by Data based on records of the National Ebola Response Center of Sierra Leone and World Health Organization.Distribution of dead cases,according to time，geographic and population characteristics and its clinical features were analyzed in the research work.Results:Case Fatality Rate (CFR) was higher at the early stage of the outbreak as 83.3％ on March，2014.It went down to 29.9％ on September,2014，and kept the lower level since then.Cumulative mortality rate of Freetown (38.9％) and districts nearer to it,as Porto Loko (39.5％) and Moyamba (37.3％)，had a lower risk of dying from EVD.Whereas districts far from the capital as Bonthe (100％)，Kono (73.2％)，Pujehun (51.6％) and Kenema(52.7％) showed higher risk of dying.As for Freetown itself,mortality rate of rural area was comparatively higher than in the urban central,45.3％Vs35.6％.The Deaths of 40-50 years group was the highest (58.3％)，0-10 years group was on the second (53.4％)，and the third was 20-30 years group (41.7％).Deaths in 10-20 years group was the lowest (33.9％)，went up.X2=9.36,P=0.03.As compared with cases with higher level education，not educated and primary education group had a higher CFR，as 44.0％ and 48％ respectively.CFR of secondary group and the tertiary group were 33.3％ and 26.7％ respectively.It showed a decrease trend as education level went up.X2=9.36,P=0.03.The average interval of deaths group is 7.72±2.63 days，which is much longer than survivals group (4.38±2.90 days)，p=0.00.The average virus load of deaths was 24.8±4.9 CT value，which was much lower than survivals (26.5±5.1 CT value),P=0.00.In logistic regression，symptoms associated with deadly outcome including weakness，difficulty breathing and confusion，with an odd ratio of 1.972,1.540 and 2.298 respectively.The most common symptoms reported between symptom onset and case detection in the 2014 outbreak of EVD were fever，fatigue，loss of appetite，vomiting，diarrhea，headache，abdominal pain，and unexplained bleeding.as soon as possible to isolate the source of infection，and suspected cases were isolated for observation cut off all communication chain，and make comprehensive treatment symptomatic treatment based.Conclusion:Several factors influenced the outcome of EVD.Coordinated international response is deemed essential to reduce the death cases.Transportation and fortune status could be the main factors relating to the mortality rate.Patients above 40 years old and children patients younger than 10 years have a higher risk of dying.Lack of education would be a great obstacle for people to get full information about EVD and to seek medical help.Clearly，being in the hospital earlier would improve the prognosis of an EVD.Patients with higher viral loads were less likely to survive.Symptoms as weakness，difficulty breathing，and confusion were most closely related to the death.