This thesis deals with the problem of Aggregation for the Singly Constrained Transportation Problem. Aggregation Technique, proposed by Zipkin, which consolidates several ``neighboring`` Origins (destinations) for solving the problem is successfully applied to our problem. In addition, to guarantee the integrality of the solution, the "Fixed-Cut Weighted" Aggregation Method is introduced. The special structure of the Constrained Transportation Problem gives us simplified error bounds of the Aggregate Problem. The Algorithm which uses basically the Augmented Treaded Index Method to solve the Constrained Transportation Problem, is developed as an iterative approach to obtain an "acceptable" solution to Original Problem.