The monograph on the basis of archival documents and graphic materials carried out a research reconstruction of the completely lost and partially destroyed temple complexes of the Agin Buryat and Khamnigan datsans. A description of their architecture is given in the context of the peculiarities of the emergence and development of Buryat cult architecture. Characteristic features of the evolution of the cult system of Agin datsans in the XIX - first third of the XX century were revealed.