Measurement of CP observables in B0s->J/psi(ee)Phi(KK) decay at the LHCb experiment

The determination of the CP-violating phase phi_s in B0s->J/psiPhi decays is one of the key goals of the LHCb experiment. Its value is predicted to be very small in the Standard Model. However, it can be significantly enhanced by contributions from effects of new physics. The first measurement of the CP-violating parameters in electron mode of the B0s->J/psiPhi decay using Run1 data collected at the LHCb will be discussed.