Since it is the scalar particles that govern the pattern of spontaneous symmetry breaking in a gauge theory, there are many situation where additional Higgs particles are theoretically desirable. We have looked for signatures for charged Higgs particles. Specially we have studied pair production of charged Higgs particles via two-photon process at HERA and SSC. It is shown that the production of charged Higgs particles via two-photon process is the most significant one at the expected HERA and SSC. The charged Higgs particles production is sensible to Higgs mas $M_h\leqslant 30 GeV$ and $M_h\leqslant 100GeV$ at HERA and SSC, respectively. Finally we have studied the possibility of observing the heavy lepton which might be considered fourth generation.