Using the theory of stratified grammar proposed by Sydney Lamb (1966), I developed a computer system to simulate the human language-using process. A new approach to representing linguistic knowledge, a goal-directed parsing strategy and a method of combining bottom-up processing with the top-down expectation are proposed and implemented. The system can automatically translate English sentences into Chinese sentences in a small task domain. Some linguistic information like syntactic structure, semantic interpretation and dynamic relations of the input sentence can also be obtained by using the system.