The main purpose of this empirical study is to look for the factors meddling with the premiums of mergers and acquisitions in U.S. Telecom and Internet industries. Through reviewing the papers relative to this subject, they provided some ideas that included several significant variables and helpful models but these papers just emphasized the bank industry or overall sectors. As this empirical research was virtually completed, there was something interesting and the conclusion was emerging. First, it indeed existed that some variables would significantly affect the premiums of mergers and acquisitions in U.S. Telecom and Internet industries. The variables are ROE of the acquirers, long- term debt to common stock of acquirers, sales of target firms, types of merger and the stock market condition. Besides, according to these variables, a model is constructed to predict the reasonable premiums and the justification of premiums is able to be accomplished. However, it is a little wondered if there is any relationship between the difference of actual and expected premiums and the acquirers’ stock performances. Finally, the compelling results are described that the stock performances of firms with good deals are better than the others with bad deals in the long run averagely, especially during the first quarter following the announcement date.