Currently the internet services with 3G technology by mobile phone operators in Thailand are different in the performance. The mobile phone operators have already launched 3G technology with 2G frequency ranges which are limited in the efficiency. This paper aims to compare the efficiency of the internet service with 3G technology by three mobile phone operators (AIS DTAC and Truemove H) in Thailand. There are three type of testing as follows: Ping to both domestic and international website Bandwidth speed test and FTP Test (upload and download) are used to evaluate the performance of these mobile phone operators. There were five places in Bangkok where are the top of the network congestion list for such testing the three mobile phone operators. The result showed that AIS gives the best performance in the ping test. Truemove H introduces the best performance in both FTP and Bandwidth speed test. The DTAC performances are moderated level for every tests.