A powertrain for a hybrid vehicle includes: a complex planetary gear set including a first rotary element, a second rotary element, a third rotary element, and a fourth rotary element; an input shaft connected with an engine and installed to be able to be selectively connected to each of the first rotary element and the second rotary element of the complex planetary gear set; a motor generator connected to the first rotary element of the complex planetary gear set; a first brake installed to be able to fixedly connect the second rotary element of the complex planetary gear set to a transmission case; a second brake installed to be able to fixedly connect the third rotary element of the complex planetary gear set to the transmission case; and an output shaft connected to the fourth rotary element of the complex planetary gear set.