The turn-on of the Large Hadron Collider this year provides great opportunities to explore physics beyond Standard Model. We examine a few scenarios in the electroweak sector and study their LHC phenomenologies. First we assess the prospect of observing neutral Higgs bosons of mass 90--130 GeV produced with W/Z in its decay to two spin-zero states, a, which cascades into bottom or tau pairs. We show that LHC observation is possible, especially in channel h → aa → bbb b with large statistical significance. Next we study signals for Kaluza-Klein excitations of electroweak gauge bosons where SM fields propagate in a warped extra dimension. Fermionic decays of these states are overwhelmed by KK gluons decays. We show that due to enhanced couplings to longitudinal W/Z and Higgs, bosonic final states can give significant sensitivity at the LHC to 3 TeV KK scale with projected LHC luminosity. Finally, we demonstrate how to systematically test Type-II seesaw mechanism for neutrino mass generation at the LHC, which introduces a Higgs triplet. For small Higgs triplet vacuum expectation value vDelta , one can look for clean signals of lepton number violation in decays of doubly and singly charged Higgs bosons, thus distinguishing different neutrino mass spectrum. For large vDelta, one needs to observe the decays H+ → W +H1 and H+ → tb to confirm the triplet-doublet mixing and the implied interaction between lepton doublet and Higgs triplet responsible for the neutrino mass generation.