<p>An analytical investigation of the excitation of the ion Bernstein wave and ion cyclotron wave by ion beam in a plasma with density ripple is reported because the ion beams have the potential to excite the ion Bernstein wave and ion cyclotron wave existing in plasma. The density ripple in plasma with a suitable wave vector results in a significant enhancement in the growth rate of the ion Bernstein wave and the ion cyclotron wave via a Cerenkov interaction. We obtain the maximum growth rate of each mode at the inverse of the Larmor radius. We observe that the growth rate of ion Bernstein and ion cyclotron waves is much affected by the variation in beam cyclotron frequency, ion thermal velocity, and rippled density of plasma for Cerenkov resonance and slow cyclotron interactions. The graphical results show that the growth rate of waves increases with an increase in the density ripple and static magnetic field. This theory of excitation of ion Bernstein and ion cyclotron waves might be relevant in fusion plasma, tokamak plasma, and plasma heating.</p>