The number of adult learners is growing rapidly in the US institutions, and these learners have become an important student population in colleges. Therefore, it is important to understand their learning strategies in order to better assist them to achieve academic goals. Meanwhile, US institutions have dramatically increased the number of international English as a Second Language (ESL) students. Thus, to better understand these students' learning strategies and help them succeed is a need. Therefore, the purpose of this study is to investigate the differences in learning strategies (i.e., cognitive and metacognitive strategies and resource management strategies) of adult learners regarding non-native status (international ESL learner vs. native speaker American learner), gender, and study majors. Two hundred and thirty-six adult learners participated in the study, and results indicated all these three variables have significant influences on these learners' learning strategies.