Determinant factors for tilted growth dynamics of dendritic arrays during directional solidification are analyzed. A vector model of solutal gradient is proposed to predict the growth direction of tilted dendritic arrays based on the competition between the preferred crystalline dynamics and the solutal diffusion interaction of dendritic neighbors. Effects of the spacing Peclet number and thermal gradient on the tilted dynamics are clarified. The predicted growth direction from this vector model is in good agreement with previous results. (C) 2011 Elsevier B.V. All rights reserved.