Generic trademarks are not entitled to exclusive rights, since due to lack of distinctiveness they deprive competitors of necessary words required to introduce goods and services and eventually, they create confusion for consumers. For some reasons, trademark may become the generic name for the category of services and goods which it belongs; In this case, death of trademark which is called Genericide will occur. Semantic gap as a result of non-existence of product or class name along with novelty of trademark, death by patent, shorter length and simplicity compare to product name and also market dominance as well as fame are among the prominent linguistic and social processes of trademark genericization. In order to confront unjustified monopoly of generic trademarks, pre-registration and post-registration, legislators can provide couple mechanisms that the most important ones are: refusal ground for registration, invalidation trial, cancellation or removal of the registry and limitation of exclusive rights. However, three questions shall remain to be answered case by case in judicial proceedings: First, what is the genus of goods and services with respect to key aspect of product? Second, trademark from point of view and perception of which group (end users, intermediaries or manufacturers) shall be deemed generic? Third, considering the evidences particularly surveys, linguistic tools, search engines and testimony of members of trade in relevant sector, what is the perception of relevant public regarding primary significance of tradeamark? The goal of this article is reviewing genericization processes, conducting comparative study of anti-generic mechanisms of trademark law and elaborating procedure of determining genericness of trademark in judicial proceedings in light of US, EU and Iran courts judgments. Finally, as and when needed, providing suggestions to overcome legislation shortcomings and gaps as well as optimizing proceedings regarding generic trademark.