Background: Paramphistomiasis is a parasitic disease of livestock animals and humans, which causes heavy economic black lashes especially in countries with advanced animal industry   Aim of Study: the current study aimed to add more information about Calicophoron microbothrium (C. microbothrium) and clarify its biological role and how its miracidia infecte the molluscan intermediate host.  In addition, a briefdescription to Bullins truncates; the morphological, structural and chronological characteristics of the various intermolluscan stages of the parasite are studied in detail. Moreover, the present work showed the effective role of physical parameters (light, temperature, salinity and gas-phase (aerobic versus anaerobic)) on egg development and hatching and the biological activities of cercaria and metacercaria.  Beside these routine techniques, PCR also was used as more advanced and accurate diagnostic technique based on the detection of nucleic acid. Where, 34 larvae and adult worms of Calicophoron microbothrium were isolated from naturally infected buffaloes. The results of the present study will facilitate the identification of this despise secular group of digeneans although its bad effect not only affect animal industry but also human health. Furthermore, the current research clears the weak points in its life cycle to aperient settling this parasite.