The paper shows normalization design for complex object schemes and its proof. The normalization for complex object schemes is not only to group objects into related relationships, but also to choose a structure for the information system which is a good representation of semantic relationships among objects that already exist in the real world. Firstly, we define object dependency based on data dependency among objects and present properties for object dependency. Then we define object normal form - normal object scheme tree and normal object scheme forest and show properties for object normal form. We present that normal object scheme forest is the desirable structure for complex object schemes. Then we present algorithm MIMI deriving a normal object scheme forest. Finally, we present and prove the properties for a normal object scheme forest produced by algorithm MIMI under a set of conflict-free ODs.