We developed a mobile study program based on a cognitive theory of multimedia learning (CTML) and designed a novel outdoor mobile learning system (QR Code Information Greenmap, QRCIG). Learners use smart phones or similar devices equipped with decoding software to decode QR codes embedded in a Green Map that deliver images and voice assistance to learners about relevant content. We observed and measured 120 fifth and sixth grade elementary school students' outdoor activities and analysed the data by using the Technology Acceptance Model (TAM). The results demonstrated that students' behavioral intention to use and attitudes regarding the QRCIG were significantly positive (correlation coefficient = 0.597∗∗). Moreover, according to the analysis, the greater the skill of the students in using the QR code was, the higher their behavioral intention to use and frequency of adoption were (correlation coefficient ranging from 0.341 to 0.852). By conducting analysis using the TAM, we proved that an education program integrated using wireless mobile devices and message image (QR code) is highly applicable in outdoor education.