Scholars have provided a large number of studies of de-phrases and de-clauses in Mandarin. However, there are still some types of de have not been fully discussed. My aim in the present research is to discover the special types of de morpheme as a complementizer. I will also focus on how to test the complementizer phrases (CPs) by means of the schema proposed by Cheng (1986), namely head-initial and head-final constructions. Although the present research does not include all types of construction with de, I find out that this scheme is suitable to analyze the aforementioned CPs after they are detected. Four types of CPs headed by de have been examined then and the analysis is proved to be on the right track. These types of CP in Mandarin Chinese are embedded relative clauses, noun clauses, adverb clauses and de-clauses in shi…de focus cleft construction.