In this paper Complete Diallel Crosses (CDC) plan is constructed using two Balanced Incomplete Block Designs and the Galois field with the same set of parametersI. The designs were isomorphic on each other and the crossing is made between the lines. The analysis of CDC plans to estimate the general combining ability (GCA) effects and specific combining ability (SCA) effects were excluded from the model. The efficiency value of the constructed CDC plan is tends to 1, and universally optimum when v is very large. The construction is also illustrated with the suitable example.