In recent days, family planning is not only a problem limitted to our country but an important problem for the while world to solve. Up to present, various methods of sterilization have been developed for population control. When a patient with a previous tubal sterilization by operative method develops any symptoms and signs of pregnancy, we strongly consider it ectopic pregnancy and intrauterine pregnancy. As the cause of sterilization failure, we think that the tubal loop sloughs away and tubal ends either unite and recanalization results or heal and failure of union results in fistula. This present study considered of the 34 cases of ectopic pregnancies and 2 cases of intrauterine pregnancies after tubal sterilization by laparoscopy and Pomeroy's method, at the Dept. of Gynecol. in Kyung Hee University Hospital, during 6 years from Jan. 1977 to Dec. 1982. Authors take result in this study retrospectively. 1. Mean age was 33.7 years for the laparoscopic tubal sterilization group, 31.5 years for the Pomeroy tubal sterilization group. 2. The number of mean gravida and parity at the sterilization was 4.9, 2.8 for the laparoscopic tubal sterilization group, 4.2, 2.2 for the Pomeroy tubal sterilization group, :respectively. 3. The number of mean artificial abortion at the sterilization was all 2.2 for the laparoscopic and Pomeroy tubal sterilization groups. 4. Mean intervals from the tubal surgery to the incidental pregnancy was 3.2 years for the laparoscopic tubal sterilization group, and 3.8 years for the Pomeroy tubal sterilization group. 5. 63.3% of the laparoscopic tubal sterilization group had problem of inadequate tubal ligation, in comparison to having no inadequate problem in the Pomeroy tubal sterilization group. 6. The previous tubal sterilized scar was found to be 6 cases (17.6%) of inner portion, 15 cases (44.4%) of midportion, 13 cases (38.2%) of outer portion at the time of operation. The tubal site of ectopic pregnancy was found to be 23 cases (67.6%) of ampullary portion,S cases ( 4.7%) of isthmic and fimbrial portion, respectively. 7. The causes of table sterilization failure were, in order of frequency, technical error (19 cases), fistula formation (6 cases) and recanalization (5 cases) for the laparoscopic tubal sterilization group and fistula formation (2 cases), technical error (l case), recanalization (l case) fo the Pomeroy tubal sterilization group. 8. As the new applicated contraceptive method in incidental pregnant patient, Authors used 2 gravigard insertion for the two intrauterine pregnancy and 34 Pomeroys' tubal ligation, 2 total abdominal hysterectomy (due to associated pelvic inflammatory disease) for the 36 tubal pregnancy.