Abstract: 43 cases of surgically confirmed liver alveolar hydatid disease caused by Echinococcus multilocularis were reported. There were 31 male and 12 female patients between 14 to 52 years of age, most of them are herdsmen of national minorities. The chief manifestation was tumor of firm, round, and irregular outline palpable on the right upper abdomen lasted for 2 months to 7 years. Jaundice appeared in 10 of the 43 patients. All patients showed positive Casoni intradermal reaction and 8 patients showed positivity to both IHA and IEP tests. Tomography, roentgenography, and radioisotope liver scanning revealed the existence of occupying lesion. Surgical radical resection or hemihepactomy was performed, however, the resectability rate was only 11.69%. The result of surgical therapy was satisfactory, no recurrence was seen in the 5 patients of radical resection followed up for 4 to 21 years. The other 6 patients with palliative resection plus sterization of the necrotizing cavity contents with formalin and drainage were also much improved in general conditions. 13 inoperable patients were treated with mebendazole, the dosage was 1.2-1.5g daily for a course of 30 days and repeated after an interval of 1 week to 1 month, the whole duration of the treatment was from 1 month to 16 months. No obvious side effects were seen. All the patients showed marked improvement and diminished size of the mass. This suggested that a higher dosage and a longer duration of mebendazole therapy may be effective.