A multiple speed automatic transmission having eight forward speeds and one reverse speed is realized by combining two simple planetary gear sets and one compound planetary gear set by five clutches and two brakes. Power is delivered efficiently and fuel consumption is enhanced due to the increased number of speeds of the automatic transmission. Step ratios of the eight forward speeds can harmonized so as to gradually decrease from the lower gear to the higher gear, thus shift-feel is be enhanced. Additionally, hill climbing ability in the reverse speed is also enhanced by increasing the speed ratio of the reverse speed.