Vibration phenomena in mechanical structures including conical shells are usually undesirable. In order to overcome this problem, this study investigates active vibration control of isotropic truncated conical shells containing magnetostrictive actuators. The first-order shear deformation theory and the Hamilton principle are handled to obtain vibration equations. Moreover, a negative velocity feedback control law is used to actively suppress the vibration. The Ritz and modified Galerkin methods are utilized to obtain results of shell vibration. The results are validated by comparison with the results of literature and finite element software. Finally, the effects of control gain value, magnetostrictive layers thickness, isotropic layer thickness, length and semi-vertex angle of the conical shell on vibration suppression characteristics are obtained in details.