This paper debates that science popularization has its own important responsibility for society and the global community. Science communicators or science popularizers should deliberately choose the content and approach for disseminating science and technology knowledge based on the evaluation and value judgment. As for that purpose, the authors further argue that communicators or popularizers should have an evaluative thinking in the process of science dissemination or science popularization. The authors hold that the evaluative thinking parallels with critical thinking is one of the most useful ways to guarantee a better play of the role of science and technology dissemination in serving our society while we confront many global problems.