The measurements of the cross-sections are presented for the production of jets in association with W and Z bosons reconstructed in their decays to electrons and muons. The results are based on 36 pb − 1 of pp collisions at \(\sqrt{s} = 7\) TeV collected by the CMS Collaboration. Jets are reconstructed with the CMS particle flow algorithm and must pass a transverse momentum threshold of 30 GeV. The study presents the ratios \({\sigma}(V+\geq \text{$n$-jet})/{\sigma}({V})\) and \(\sigma(V+\geq \textit{n-{\rm jet}})/\sigma(V+\geq(n-1)\)-jet). The comparison between the data and the Monte Carlo prediction is also showed.