This research aims at making a thorough analysis on the computer aided design (CAD) employed in landscape design in an attempt to make computer play a better role in landscaped design and improve the quality of the design. This essay firstly gives a picture of the current development of CAD employed in China’s landscape design, then points out the problems and provides relative solutions. Then it comes to the application of CAD. Judging from the process of CAD landscape design and common CAD software programs, this essay introduces several commonly used software programs and explains the advantages and shortcomings of these programs to allow users to choose according to their needs. Finally, since virtual reality is the latest computer technology, this essay also gives detailed analysis of virtual reality’s application to practical use. It explains the process of modeling of virtual reality and gives further demonstration of CAD’s advantages in landscape design. Although there is still a lot to be advanced, the trends of CAD are promising. CAD and traditional landscape design are complementary to each other and will make great progress.