preliminary activities of this study was conducted in the city of Kerman from 1991 to 1994 to carry out a control program on hydatid infection.a total of 6500 stary dogs were killed by bullets or baited with strychnine.of which 4500 dogs were killed during 1993 through spring of 1994 and rest during 1994 in rural and urban areas of the city of Kerman.simultaneously,276 pet digs and sheep dogs were treated once every six months with praziquantel for a period of one year.the average infection rate was 5% in 1993,however there was no significant difference between the values in four seasons.in contrast ,a decreasing trend was observed in infection rate from spring(5%) through winter(1.5%) of 1994.there was a sharp drop in the prenalence of infection in sheep in winter of 1994,while in goats this reduction appreared earlier:it started in summer to the end of winter of the same year.a steady decreasing trend in the rate of hydatid infection in slaughtered animals was observed during 1994(5.4% in April 1994 and 0.5% in March 1995).although this study is limited to the city of Kerman,it is more or less indicative of condition and distribution of infection in the country.any similar attempt that eliminates dogs in the life cycle of this parasite,will reduce the incidence of hydatid disease in humans and animals.