Abstract: The study of Di-boson production represents an important part of the Electroweak Physics program in 1.96 TeV p p-bar collision at the CDF experiment . Di-bosons are of great interest because they provide unique opportunities to test the Standard Model at the TeV scale. Moreover, the process WW+WZ -> l nu + jj shares the same event topology of WH -> l nu + b b-bar, the golden channel for low mass Higgs searches at CDF. As a consequence, establishing Di-boson production with jets in the final state represents a crucial milestone for the development and understanding of techniques used in Higgs boson searches at the Tevatron. In this seminar, we will focus on the observation of Di-boson production at CDF in the lepton-missing Energy +jets final state by looking at the Di-jet invariant mass.