This research aims to determine how the application of ta'awun in the joint responsibility system in the Assakinah cooperative. The method used in this research is a qualitative approach with a case study method. The object of this research is the Assakinah cooperative in Sidoarjo. Data was collected by interviewing five informants, namely, head of the cooperative, the secretary, treasurer, group assistant and group leader. The results of this research indicate that the implementation of the joint responsibility system that exists in Assakinah cooperatives is in accordance with two Islamic teachings, namely, musyawarah or mufakat and mutual cooperation. However, the joint responsibility system that exists in Assakinah cooperatives is not yet fully joint responsibility. This is because in practice, members that are unable to pay their debts, not always getting help from the group.Keywords: Ta’awun, sharia cooperative, Joint Liability, joint responsibility.