This experimental study examined how the reading and writing development of sixth-grade L2 students was affected by syntactic enhancement. Visual-syntactic text formatting (VSTF) technology, which visualizes syntactic structures, was used to convert a textbook to the one with syntactic enhancement. The sample (n = 282), which was drawn from a larger study conducted in Southern California, was a mixed population of English proficiency levels: low-proficiency L2 students (n = 113) and high-proficiency L2 students (n =169). Over a school year, VSTF students read their English language arts (ELA) textbooks in VSTF on their laptops and control students read their regular block-formatted textbooks either on their laptops or in print. Observations and interviews revealed that VSTF reading facilitated student engagement in ELA instruction by drawing students' attention to syntactic structures. The results of the California Standard Tests (CST) before and after the intervention were examined to evaluate participants' learning outcomes. Although high-proficiency students did not show a significant improvement on the post-test, low-proficiency made significant gains on two subtests of the CST: written conventions and writing strategies. These findings suggest that VSTF reading may facilitate improving syntactic awareness, which is essential for L2 students to develop their English reading and writing skills in academic contexts.