This study is aimed at Exploring the usefulness of Mobilc Assisted I anguage Learning in enhancing English vocabulary acquisition of First year students at Sripatum University as a 21st Century learning tool in the classroom. The Main focus is 1.) to investigate how first-year students use their mobile devices as tools in English vocabulary learning, 2.) to identify the Mobile devices applications that the students use in English vocabulary acquisition and finally 3.) to compare students' vocabulary knowledge after using MALL through Pre-test and Post-test.