Summary: Activation of delta opioid receptor system produces a behavior profile distinct from that of other opioids, therefore the design of new delta selective agonists is actual. The quantitative structure-activity relationship can be predicted using different mathematical models. The aim of the presented study is to find a relationship between structures of both-receptor and ligand, characterizing biological activity.The relationship of the quantitative parameter of in vitro bioassay with the data from the docking was modeled with first to third degree polynomials using the least squares method. It was established that the polynomial of the third degree has the best fit, so it could be applied for determination of the quantitative structure-biological activity relationship.