Cu-Ni is one of good materials as a substrate for producing biaxially textured YBCO coating conductors. The non-magnetic CuNi alloy substrate was prepared by rolling assisted biaxially textured substrates (RABiTS) technology. The orientation as a function of annealing temperatures for the as-obtained CuNi substrate was characterized by XRD and EBSD. The results show that the heat treatment process is an important factor for the texture transition in CuNi alloy substrate. The percentage of the cube texture in CuNi alloy substrate obtained by the optimized heat treatment process is as high as 97.0% within a tolerance angle smaller than 10o. The optimized heat treatment process is holding the tape at 950 oC for 60 min