Abstract: Effects of surface treatments of p-type Cd_0.8Zn_0.2Te crystals on the electrical properties of contacts are studied by Atomic Force Microscopy (AFM). The electrical properties and mechanism of contacts using vacuum deposited An, Al, In and electroless platted An as contacting layers are also studied. It has been shown that electroless platted An film can form a heavily doped p⁺ layer on Cd_0.8Zn_0.2Te smooth surface, and the ohmic contact on "type Cd_0.8Zn_0.2Te can be easily obtained using electroless platted Au than that using vacuum deposited An, Al and In. The post-annealing treatment of electroless platted An film can improve the ohmic quality of contacts and enhance the adhesion between contacting layer and Cd_0.8Zn_0.2Te crystal surface.