In object-oriented systems, heavy message sending has slowed down the execution efficiency. Most of the current solutions are based on the message tables according to the class-hierarchy to develop more efficient method searching algorithms. In this paper, an approach with little space overhead and constant dispatch time will be proposed. The proposed algorithm can be applied in both typed and untyped object-oriented languages. For typed languages, the space overhead is not greater than the conventional ones, but it can dispatch methods in the same situations as untyped languages. For untyped languages, the constraint for dispatch is not lessened and the space overhead is not much higher, but it can dispatch method in constant time. Based on the comparison with conventional approaches, the proposed approach demonstrates its advantages on space overhead, dispatching speed, and applicability. Several cases study are presented as a comparison with existing run time dispatch mechanisms.