At the early design stage, a designer would develop a design through reviewing various alternatives. However, the limitation of human information handling capacity restricts what makes various alternatives. A way to overcome the limitation is to create the alternatives with computer power and the generative design concept with computer has been used. For the generative design, even if a great deal of methodologies has been presented, the core of methodologies would be the process of shapes which examine interrelationship among shapes and how shape can be changed with the interrelationship. The interrelationship can be represented as rules. To represent the rule, the shape grammar is suggested by Stiny in 1972 with the article of "Shape Grammars and the Generative Specification of Painting and Sculpture". The aim of this paper is to present a way of using generative design based on shape grammar for generating alternatives in 3D manner.