The N+H 2 reaction has attracted a great deal of attention from both the experimental and the theoretical community, and most of the attention has been paid to the first excited state N( 2 D) atoms in collisions with hydrogen molecules and the scalar properties of the reaction. In this paper, we study the stereo dynamical properties and calculate the reaction cross sections of the N( 4 S) + H 2 (v=0, j=0, 2, 5, 10) → NH(X 3 Σ − ) + H using the quasi-classical trajectory (QCT) method on an accurate NH 2 potential energy surface (PES) reported by Poveda and Varandas [