This paper presents the initial findings of a comprehensive geological survey of the “Muji volcano group”. Through extensive fieldworkanda systematic analysis of the volcano group, the author introduces innovative concepts such as “hot volcano” and “cold volcano”. The classification incorporates mud volcanoes, categorizing the Muji volcano group as a “cold volcano”. The “Muji volcano group” is distributed along the Muji River valley, encompassing at least 63 volcanic cones of various sizes. Thirteen of these cones have a base diameter exceeding 50 m and a cone height surpassing 5 m.The cones exhibit numerous craters at their summits, often containing substantial water. The primary composition of these cones is limestone, and hydrochemical analysis of the crater water reveals elevated levels of Ca2+and HCO-3, aligning with the abundant carbonate rocks in the surrounding area. These volcanic cones primarily result from the dissolution of carbonates by groundwater, spring water, and running water in the Muji River valley. The expelled materials are deposited on the surface, forming structures akin to volcanoes. Despite their outward resemblance, these formations deviate from traditional volcanoes and differ from typical mud volcanoes. Consequently, they are classified as calcareous springtype “cold volcanoes”.