Temporal-spatial metaphors can be differed across languages, and such cross-linguistic influences may affect people’s spatial conceptualization of time. Mandarin (including gestures) has different spatial metaphors for time than Chinese Sign Language (CSL). This paper investigated whether native Mandarin speakers’ mental space-time mappings change after learning CSL for 14 weeks. Sixty native Mandarin speakers who had no prior knowledge of sign language took a pretest and posttest of space-time mappings before and after taking a CSL course. The results showed that participants changed their temporal-spatial mappings after learning CSL. Specifically, they had more sagittal space-time mappings and fewer lateral ones than before. They also had more “future-in-front/ past-in-back” mappings consistent with CSL space-time mappings. Furthermore, these changes were more significant in high-proficiency learners than in low-proficiency learners. Our results not only demonstrate an effect of bodily experience on time conceptions, but also suggest that sign language can impact spatial temporal reasoning.