Abstract: In order to provide theoretic direction for interface design and control of WC/Fe composite, the dissolution thermodynamics of WC particles in the matrix was analysed for WC particles reinforced gray cast iron matrix composites, and the experimental techniques such as DTA, OM, SEM and XRD were used to investigate the interactions between the tungsten carbide (WC) particulates and the gray cast iron matrix, and the dissolution of the tungsten carbide particulates (WC) in the matrix was investigated. The results show that HT300 melting has a good wetting with WC particles, the surface of WC particles is dissolved obviously when the highest temperature of the system is 1450℃, and WC particles begin to be dissolved in the HT300 matrix as the temperature is about 1281℃. When the system temperature rises to a certain point, the resolution reaction of WC (WCW₂C＋C) occurs and the diffusion of elements can accelerate the dissolution of WC particles.