We report a search of the decay B c to Bs pi with a data sample of 20.65 fb^(-1) in proton-proton collisions at sqrt(s) = 8 TeV collected by the CMS experiment at the LHC. With 81+- 19 events observed, the ratio of branching fraction, B(B c to Bs pi)/B(B c to J/psi pi) is measured to be (1.7+0.5-0.7(stat.)+-0.5(syst.))x10^3.