Objective: To investigate the preventive measures and relative factors of the onset of ectopic pregnancy in different periods.Methods: Retrospective analysis of the relative factors was made in 178 cases of ectopic pregnancy in 1994(the first group) and 414 cases in 2004(the second group)

including age

marital status

gravidity

parity

occupation

education and past history.Results: The ratio of ages under 20 years and between 20 and 25years in the second group was significantly higher than that in the first group

but the difference of average age between the two groups was not significant.The percentage of the unmarried and the nonparous was respectively 7.87% and 35.96% in 1994 group

28.02% and 57.01% in 2004 group(P<0.01).The number of farmers with ectopic pregnancy decreased markedly

while students

the jobless and staffs increased in number.According to past history

intrauterine device was the main factor in the first group(69.67%)

whereas the patients with pelvic infectious diseases(61.83%) and previous ectopic pregnancy(15.22%) increased in the second group.Conclusion: The relative factors of the onset of ectopic pregnancy changed in recent 10 years.To reduce the incidence of ectopic pregnancy

the preventive measures must be strenthened.