This paper discusses the activity of patent of the national fharmaceutical industry, in particular the dynamics of patent of local companies is compared with the transnational ones, between 1980-2006. In an industry based on the science and of easy imitation-like it is the case of the pharmaceutical industry-, the patent is the natural technological strategy of protection and the mean of appropriation of the derivate benefits of the innovation. This work seeks to demestrate that a drastic change of the system of patents, it can generate two effects in oneself sector: to impel of to destroy a competitor of the career of patents in fucntions of the accumulated technological capacities, such it is the cas of the mexican pharmaceutical industry. The results give evidence of the defeat of the mexican pharmaceutical companies in relation to the transnational ones.