The dynamics of interfacial evolution of a particle in the binary alloy melt affected by anisotropic surface tension is studied by means of the multiple variable expansion method. The resulting analytical solution reveals the critical radius of nucleation in the binary alloy melt and the inward growth mechanism of interfacial evolution of the particle induced by the anisotropic effect of surface tension in the initial crystal growth immediately after nucleation. After nucleation, because of the anisotropic effect of surface tension, some parts of its interface grow outward, while some parts first grow inward in the initial crystal growth. Until the inward growth attains a certain distance (which is defined as `the melting depth'), these parts start to grow outward with other parts. During such a process the interface of the particle will form a remarkable concave and convex formation with the ear-like shape whose radius for some parts of the particle may be less than the critical radius of nucleation. The solute diffusion in the binary alloy melt changes the critical radius of nucleation and decreases the anisotropic effect of surface tension on interface deformation.