With the development of society, those newly-coined words are widely spread and used in people’s economic, social and cultural life. Besides, due to the advanced internet and network, more and more internet new words are coined and the speed of it is increasingly faster. There is no doubt that those internet new words are not only popular among young people, but also adopted by people of all the ages. The author in this paper aims to study and analyze the occurrence and spread of the words newly-coined from sociological, psychological and linguistic perspectives, and in the mean time to observe the specific mentality of modern people as well as all kinds of social phenomena. This paper mainly focuses on the analysis of new words in both China and South Korea from the perspectives of psycholinguistics and sociolinguistics, among which the former concludes three parts of psychology of filling invacancies, psychology of language minimization and imitative, conspicuous motivations and poppsychology, while the latter involves four parts of reflection of life style, economic phenomena, appearance supremacist and pursuit of health. Through the analysis and study of the newly-coined words in China and South Korea in the light of sociology as well as psychology, the author finds that the occurrence and spread of new words in both the two countries is greatly influenced by society and people’s mentality, resulting in similar types of new words emerging in the two countries. Thus, fundamentally, new words are coined and popularized because of the integration of human’s specific mentality and social phenomena.