Environmental education in the academic level is the most effective way to increase environmental awareness of college students particularly in handling plastic waste problems. This study aimed to compare the student’s knowledge and behavior on plastic waste problem between environmental science and social science students and to examine the correlation of knowledge and behavior to reduce plastic waste. Through survey of 98 students of National Chung Hsing University, Taichung, Taiwan, we compared the students’ knowledge and behavior on plastic waste problems by t-Test and Chi-square analysis, and we used Kendall’s rank correlation to evaluate the correlation of knowledge and behavior. This study found that the differences in majors resulted in the significant differences in knowledge on the negative impacts of plastic waste, where the students who are majoring in environmental sciences have higher score than the students in social science. Relating behaviors, the differences in majors also resulted in the significant different behaviors to reduce plastic usage, where the students with major in environmental sciences have the better behavior to reduce plastic usage for daily life than the social science students. These behaviors were shown in purchasing products with plastic packaging, preparing shopping bag, re-using plastic bags, taking own meal box, and having food on the sites to reduce single used plastic package. This study also found the positive correlation between environmental knowledge on plastic waste and behavior to reduce plastic waste in the daily life.