Taking into account the challenges of EFL vocabulary learning for East Asian learners, this study developed a set of experimental English vocabulary material with pictographic glosses which may stimulate students' situational interest (with dimensions of exploration intention, instant enjoyment, novelty, attention demand, challenge, and total interest) in learning vocabulary and facilitate their vocabulary retention. To examine the effectiveness of the learning material, this study utilized a within-subjects quasi-experimental design. The participants were 108 graduate and college students who used the learning materials presented in text-only, text-with-picture, and pictographic formats in an online learning system. Results revealed that students' retention performance on the pictographic materials was significantly higher than on the text-only materials, while no significant differences were found between the pictographic and text-with-picture materials. The perceived situational interest in the pictographic material was significantly higher than in the other two formats. The results suggest that the pictographic vocabulary material could trigger EFL learners' situational interest and help to promote their English vocabulary learning. It could therefore serve as a novel approach to designing EFL vocabulary materials for multimedia environments.