In this report we wanted to remind parts of principles and methods of conservation and restoration of pottery objects, and to present reconstruction process of two large pottery Jar (Khomreh) belong to Sassanian period during a written and illustrated report. also, we explained the difference created when choosing materials and methods. The jars were obtained from excavating Varamin Plain by Dr. Morteza Hesari in 2017. They were restored at the conservation pottery workshop of the Research Institute of Cultural Heritage & Tourism Research center for conservation and restoration of relics (RCCCR).