Abstract: Interword spaces play very important roles in spaced alphabetic language for delimiting word boundaries. When spaces between words are removed. reader's reading efficiency will be reduced significantly, word identification also will be disrupted. In unspaced languages, such as Thai, inserting spaces between words was proved to improve reading. Although Chinese script is normally printed as continuous strings of characters, word identification is one of the critical processes in reading. Number of studies explored whether inserting spaces between words could improve the reading efficiency of Chinese readers, and found no evidences supporting any facilitation or disruption of interword spaces had on reading. Researchers provided that the null effect was due to the trade-off between the facilitation of inter-word spaces and the interference of unfamiliar inter-word spaces text. Studies using Chinese second language beginners as the participants, who were much less experienced in reading Chinese texts without spaces between words, to investigate the effect of inserting word spaces on their reading. They found that participants benefited from introducing the inter-word spaces. However, Chinese second language beginners still have experiences in reading Chinese texts, at the same time, they were less skilled Chinese readers which may confuse the results. In current study, we manipulated the presenting direction of Chinese text, including normal text presented from left to right and text presented from right to left, which the readers had no experience in reading such a text. We also manipulated the appearance of spaces between words (presented vs. absent) and frequency of the target words (high vs. low). 48 undergraduates participates were asked to read sentences and their eye movements were recorded using the Eye Link 1000 Plus Eye tracker. Results of sentence level analysis showed that the efficiency of reading the text written from right to left was significantly lower than that of reading the normal presented text written from left to right, which was manifested as longer average fixation time, more fixation counts, and longer total reading time. Inter-word spaces did not promote participants’ reading efficiency when they read normal presented text written from left to right, which is consistent with previous studies. However, when they read the text written from right to left, word spaces facilitated readers’ reading compared to reading text without spaces due to readers spent shorter total reading time and made less fixations. For the word analysis, we observed a significant frequency effect which showed that the fixation time spent on high frequency target words was significantly shorter than that on low frequency target words, but such word frequency effect were not qualified by the presentation direction or the appearances of word spaces. In addition, we also obtained space effect and presenting direction effect due to readers spent shorter fixation durations on target words with inserting interword spaces(and reading from left to right) compared to process unspaced words (reading from right to left).These findings suggested that introducing word spaces as word segmentation cues facilitated Chinese reading of readers who were lack of such reading experience, which supports the trade-offs hypothesis. Moreover, introducing word spaces promotes reader's word identification.