Student should improve their communication skills whereas they are in school and college to enhance their adaption for the 21-century skills requirement. The aim of this study is promoting students' oral-communication skills through Multimedia Based Integrated Instruction (MBI 2) on earth-science content. The research method that is utilized in this research is embedded mix methods toward 35 seventh grade students that consist of 17 males and 18 females. Oral-communication skill rubric which has been developed is used to assess students' oral-communication skill. The aspects that assessed are eye contact, intonation of speech, content, enthusiasm, and mannerisms & body language. We assessed each aspect using the rubric and then interpret it into categories which are need an improvement, fair, good and excellent. The result shows that the average score of five oral-communication skill aspects in every meeting are 8.40 (earth structure sub-content) that is categorized as Fair, 13.75 (earthquake sub-content) that categorized as Good, 14.83 (tsunami sub-content) that is categorized as Good and 15.67 (volcano sub-content) that is categorized as Good. In conclusion, MBI 2 can promote students' oral-communication skill of seventh grade on earth science content.