This paper aims to investigate effects of media evolution on the generation of sign, signification and communication in the evolutionary process of media. For the purpose of this study we take an example of SNS media which recently are afresh coming on. Some results from the studies are putting together as follows. 1) Sign is not stable but generated and transformed in the semiotic process, while media is evolved. 2) sign, which is in itself not material, has the signifier to be realized in material dimension. 3) In long-term material characters of media tend to have impact on consciousness of sign-user. 4) Meanings of sign are generated from differences between signifiers. 5) Communication is the conveyance and reception of signs from the semiotic point of view. With these semiotic results we explored the signification, communication, and sign-generation in the case of SNS and got findings as follow. Web site is a sign, which is made of signifier as internet and signified as contents. Signification works on the basis of Blogs as paradigm and networking as syntagm, whereas communication has two levels of Information or message delivery and it`s meaning creation. The former is composed of participants, web site, social value, internet, shared minds and the latter corresponding to the former is constructed with functions respectively of the emotive and conative, the poetic, the referential, the phatic, and the metalingual.