Abstract: The leakage dissolution performances of hydraulic RCC under the permeation of soft water was investigated. First, by the leakage dissolution experiments of hydrated cement paste and mortar, this research acquires the result that the main leakage dissolution part of cement-based materials is hydrated cement paste. Second, through the leakage dissolution experiments of hydraulic roller compacted concrete with different contents of fly ash or additive, it is concluded that the most important factor affecting the leakage dissolution performances of hydraulic RCC is its permeation coefficient. Furthermore, this paper discusses the stability and durability of leakage dissolution of hydraulic RCC.