Abstract
Competition is a status, further, a dynamic process. Based on the theme of Fair Competition Law, "Relevant Market” was defined as “the business competitive market” where enterprises render or sell no matter products or services and could be understood from two dimensions, which are relevant product market and relevant geographical market. Inevitably, digital convergence creates huge impact on current definition of relevant market. Rapid technological evolution has increased the mutual substitution between physical products and intangible services, thus the literal definition and the boundaries of two are getting vaguer and vaguer. Due to the certainty and predictability of legal frame, the author suggests that elements of timescale need to be considered when the relevant product (even should be defined case-by-case) is referring to the telecommunication industries. The author also recommends that the Test of Spatial Substitutability to demonstrate the bound of geographical market rather than the traditional Shipment Test to telecommunication practices is more capable to avoid problematic applications.