In this paper, from many multi-criteria models in making decision, a classical technique for order preference by similarity ideal solution (TOPSIS) approach has been described. This method is based on the concept that alternative should be selected which have the shortest and the farthest distance from the negative solution. Some of the advantages of TOPSIS methods are the following; simplicity, rationality comprehensible concept, good computational efficiently and ability to measure the relative performance for each alternative in a simple mathematical form. The TOPSIS algorithm to determine the most preferable choice among all possible choices is presented in the case when we have exact, as well interval data. Finally, an example is shown as application of this procedure in negotiation. By implementing TOPSIS algorithm we can order offers in buyer-seller transaction. The paper is organized in the following way. The Introduction presents a short overview of the decision making steps as well MCDM techniques. The details of the proposed TOPSIS method with exact and interval data are given in Section 2. An application of this approach is described in Section 3 to order offers in buyer-seller transaction. Finally, the last Section contains some concluding remarks and possible perspectives.