The purpose of this article aims to analyze the effect of word-word space in written Chinese to advanced non-native speakers when they read and process Mandarin texts. The participants have performed one online reaction time experiment and another one offline pencil-paper test. The results indicate that the structure of word segmentation in written Chinese texts have play an effective role in sentences' semantic processing, and the length and difficulty of sentences stimuli have also displayed significant function for their Chinese sentences processing. However, the results of offline test show that the combinational amount of segmental words have not affected the texts materials processed by advanced L2 participants. These results suggest that word boundary can facilitate L2 learners of Mandarin Chinese in processing text during their reading. Apart from theoretical implications, this article also proposes a new pedagogical approach to teaching text segmentation in Chinese, which can be useful in instructing Chinese as a second or foreign language.