This research for introduce and paleontology of Early Cretaceous Rudist in the Middle Tethys Ocean, stratigraphic section of the kalleh pahnoo has been selected from the Shahkouh Formation in Central Iran (Khor and Biabank region). The studied section consists of 120 m thin layer to massive limestone. Studies on 106 specimens collected and prepared from this section have led to the identification of specimens from the Hippuritoid class. Overall, 2 genera and 5 species of Radiolitidae family and 1genera and1 species from Requienidae family were identified. According to studies age of Kalle pahnoo deposits, late Aptean-Albian was suggested. Paleoecology studies on growth form and shapes of rudist communities indicate relatively warm environment with low salinity in this region. elevated rudists' morphology revealed a relatively calm and quiet environment, with continuous deposition.