The authors have made simulation experiments on the interactions of valcanic gas-hydrothermal solutions with subvolcanic-volcanic rocks (diaba- se, andesitic-tdff, a.ndesite and tuffaceous sandstone) based on field observa- tions of three iron ore deposits in volcanic rock areas of Cihai and Yamansu, Xinjiang and Huanggangliang, Inner Mongolia. The results of experiments has proved that paragenetic associations of the minerals of metasomatic rocks formed at 380-7000℃ temperatures and (250-800) × O.1MPa pressures are similar to those in the aforementioned three iron ore deposits, are TFe= 11.89-3881.89mg/1 is extracted from sdbvolcanic-volcanic rocks. It follows that metasomatism of the wall rocks of previo}xsly formed subvolcanic- volcanic rocks by late volcanic gas-hydrothermal solutions continuously rising along structural zones, led to the extraction of a great quantity of iron from these rocks and to the formation of the Cihai, Yamanstt and Huanggangliang(western part) iron deposits under the favorable tempera- ture, pressure, and other physico-chemical conditions.