Three experiments investigated Chinese relative clause processing with children, youths and elders using sentence-picture matching and self-paced reading methods. In Experiment 1, we found that object-extracted clause were easier to comprehend than subject-extracted clause , and object-modified relative clause (i.e., object-modified subject-extracted clauseobject-modified object-extracted clause) were difficult to comprehend than subject modified relative clause (subject-modified subject-extracted clausesubject-modified object-extracted clause). Importantly, this paper also found 5-6.5 ages may be critical for children to comprehend RCs in Chinese. Experiment 2 also showed that S-ORCs were easier to comprehend than S-SRCs for youths and elders. Further, elders have more difficulty comprehending RCs than youths. Experiment 3 indicated that there were no significant differences in difficulty between O-SRCs and O-ORCs, and no differences were found between youths and elders. In general, our findings gave support to predictions of working memory-based theory, and also indicated that RCs processing has an intricate course. Many factors such as syntactic, language specificity, experience, personality, must all be considered in sentence processing.