The classical free shear layer flow includes: jet, mixing layer and wake flow. All of those are important in many practical applications. The developing flow in both plane jet and wake is dominated by large-scale, wavelike coherent structure, If the two flows coexist, then the characteristic properties in the flow field will be different. With the aid of X-wire measurements, both streamwise and transverse velocity componments are investigated. The evolution of coherent structure and the interaction between the jet and wake flows are discussed.