nÃo hà / The privatization of the telecommunications sector in Brazil, caused structural changes in the market, going from state monopoly to a nearby structure of competitive markets. To prove this notion of evolution, were calculated for the mobile industry, some indices of industrial concentration, namely: market share, concentration ratios (CR), Herfindahl-Hirschman Index (HH) and Theil entropy index (ET) by the number of cell phones by operators (inThousands) in the period 2000 to 2010, with all these measures confirming the decentralization of the mobile market in the last decade. / A privatizaÃÃo do setor de telecomunicaÃÃes, no Brasil, provocou mudanÃas estruturais nesse mercado, que passou de monopÃlio estatal a uma estrutura prÃxima de mercados competitivos. A fim de comprovar essa noÃÃo de desconcentraÃÃo, calcularam-se, para o setor de telefonia mÃvel, algumas medidas de concentraÃÃo industrial, quais sejam: Market Share, RazÃes de ConcentraÃÃo (CR), Ãndice de Hirschman-Herfindahl (HH) e Ãndice de Theil (ET), atravÃs do nÃmero de celulares por operadoras (em Milhares), no perÃodo de 2000 a 2010, com todas essas medidas confirmando a desconcentraÃÃo do mercado de telefonia mÃvel na Ãltima dÃcada.