This chapter examines optional projections in Chinese: TopicP and FocusP. It offers a new analysis of topic constructions in Chinese, discusses ex-situ cleft-focus and ex-situ lian ‘even’ focus constructions. The chapter explores syntactic positions of optional projections in the left-periphery. Information structure attempts to map different informational components, based on their discourse functions, onto syntactic structures. Although a configuration based on “theme-rheme” or “topic-comment” represents a syntactic structure, each of these components, such as “theme/topic” or rheme/comment”, is clearly defined in terms of its semantic interpretation or discourse function in a given sentence. The fronted constituent is separated from the rest of the sentence by an intonational pause or by a “comma intonation” or by a hesitation pause. Rheme or comment bears new information, which is also called “Focus domain” by Erteschik-Shir. As syntactic derivation, topicalization results in ‘topic-comment’ pattern. Rizzi proposes an independent functional projection, TopicP, to host topic phrases.