Abstract: With the widespread use of social network, the function named like become more and more popular, which has drawn a lot of voice of doubt at the same time. However, it is worth researching on what did like bring to social network, and how did the function influence our daily life. In this paper, researchers select the student of Southwest Jiaotong University as a case, and use observation, questionnaire, and interview to explore the motivation and the effect of using like from the perspective of effect of communication. In the end, researchers discover the significance behind the function.