This paper first of all reviews transitivity studies within Systemic Functional Linguistics by Halliday, Matthiessen, Martin, et al. and Fawcett. Then it outlines developments and further developments of transitivity in China. The sketch of transitivity studies both abroad and at home reveals the main problems concerning existing transitivity studies. And the solution to the problems helps us to improve the English transitivity system network and to construct a comprehensive Chinese transitivity system.