This paper deals with development of triangular fnite element for buckling and vibration analysis of laminated composite stiffened shells. For the laminated shell, an equivalent layer shell theory is employed. The frst-order shear deformation theory including extension of the normal line is used. In order to take into account a non-homogeneous distribution of the transverse shear stresses a correction of transverse shear sti.ness is employed. Based on the equivalent layer theory with six degrees of freedom (three displacements and three rotations), a fnite element that ensures C0 continuity of the displacement and rotation felds across interelement boundaries has been developed. Numerical examples are presented to show the accuracy and convergence characteristics of the element. Results of vibration and buckling analysis of sti.ened plates and shells are discussed. Ó 2001 Elsevier Science Ltd. All rights reserved.