A powertrain for a hybrid vehicle may include a complex planetary gear set including four rotation elements having first, second, third, and fourth rotation elements; a motor-generator fixedly connected to the first rotation element of the complex planetary gear set; a first brake configured to selectively connect the second rotation element of the complex planetary gear set to a transmission housing; an input shaft connected to an engine and configured to be selectively connectable to each of the first rotation element and the third rotation element of the complex planetary gear set; and an output shaft connected to the fourth rotation element of the complex planetary gear set.