Commutation test is a examination of replacing one element by another which will show the meaning of original choice. (Lacey,1998) By undertaking the commutation test we could understand if the original element is the most suitable choice or not. In our packaging design, we have put a cow cartoon character on the left surface of the side of the screw lid alone with the green grass(Fig.1). The grass has the representational meanings of the freshness and the connection to the nature, and the cow shows the source of where dose the milk comes form. When we undertake the commutation test, we have replace the cow character with a rabbit character(Fig,2), the rabbit has given us the impression of staying underground, a house pet and cuddling feeling, all of our groupmates agree that the cow character suits our theme and design better than the rabbit.