Abstract: Previous studies of phase mainly focus on one language. They aim to reveal the relationship between features of phase and classifications of verbs,but usually neglect the distinction between simple phase and complex phase. From the perspective of Systemic Functional Linguistics,this study distinguishes simple phase from complex phase,and points out that simple phase refers to the internal temporal feature of a clause which is only revealed by the clausal element realizing the process meaning. Based on this concept,the present study makes a comparison of realizations of simple phase in English and Chinese,and finds that there are similarities and differences between them.