A frequency domain electromagnetic algorithm boundary element method is applied for computation of Casimir forces between arbitrary materials with arbitrary geometry. Considering electric and magnetic surface current distributions,Casimir force of two objects in terms of interactions of surface currents is obtained. Casimir effects between dielectric objects embedded in dielectric fluid are presented and numerical conditions of repulsive Casimir force are investigated. Non-zeropoint energy Casimir force calculation method is provided. It can be used for design of realistic MEMS.