Abstract: Through self-paced reading paradigm, with arithmetic equations as the primes and English relative clauses as the target structures, this experimental study explored the cross-domain structural priming from arithmetic equations to English relative clauses in sentence reading comprehension by Chinese college English majors.The results of the two experiments show that high-attachment arithmetic equations processing facilitated the processing of high-attachment English relative clauses and low-attachment arithmetic equations processing facilitated the processing of low-attachment English relative clauses.These results indicate that there is cross-domain structural priming in L2 comprehension, and arithmetic equations may share abstract structural representation with L2 relative clauses.