The purpose of this study was to investigate the effects of different teaching strategies (text-based concept mapping vs. image-based concept mapping) on the learning outcomes and cognitive processes of mobile learners. Eighty-six college freshmen enrolled in the "Local Area Network Planning and Implementation" course taught by the first author participated in the research. This study randomly selected one class as the experimental group and the other as the control group. Students in the experimental group used image-based concept mapping to finish assigned tasks and those in the control group used text-based concept mapping to complete the same tasks. Quantitative analysis combined with qualitative analysis was used to examine the learning outcomes and cognitive levels of the students, as defined by the revised Bloom's taxonomy. The results showed that (1) there was no significant difference in students' learning achievements, (2) the group using image-based concept mapping showed higher level than the text-based group in the dimension of understanding and creating and (3) the image-based concept mapping strategy was more complete and diverse than the text-based concept mapping strategy.