In developing software using model-driven approach, the key technique used is model transformation. Model transformation requires the development of transformation rules. Design of the transformation rules will allow the rules to be understood by people without the need to know the language to write the rules. This paper proposes a notation for designing the transformation rules. The abstract syntax, concrete syntax, semantics and well-formedness of the proposed notation are explained here. Examples and experience in using the notation are also given. © 2008 IEEE.