Orientation plays an important role in layered manufacturing since it affects the build time, cost and part quality directly. This paper proposes to use AM (Additive Manufacturing) feature and Multi-attribute decision making to select an optimal build direction for a given part with its production requirements. AM feature is defined and associated with AM production knowledge to deduce the available build directions. Then key attributes of a build orientation are identified and used for the representation of alternative orientations. A Grey Incidence Evaluation model is adopted for decision making to select the optimal orientation from alternative orientations according to adjustable production requirements. An example part is used as a case study the illustration of the proposed method.