In 2016 US election, social media played a vital role in shaping public opinions as expressed by the news media that have created the phenomenon of polarization in the United States. Because social media gave people the ability to follow, share, post, comment below everything, the phenomenon of political opinions being spread easily and quickly on social media by the news agencies is bringing out a significantly polarized populace. Consequently, it’s very important to understand the language differences on Twitter and figure out how propaganda spread by different political parties that influence or perhaps mislead public opinion. This talk will introduce the relationship among the social media, public opinion, and news media, then suggests the method to collect the tweets from Twitter and conduct sentimental and logistic regression analysis on them. Furthermore, this talk points out the special aspect on the relationship between the polarization and the topic of this conference (fake news, disinformation and propaganda). Main points: - situation in Taiwan - research on fake news - methods for fighting fake news