Present disclosure provides a hybrid semiconductor transistor structure, including a substrate, a first transistor on the substrate, a channel of the first transistor including a fin and having a first channel height, a second transistor adjacent to the first transistor, a channel of the second transistor including a nanowire, and a separation laterally spacing the fin from the nanowire. The first channel height is greater than the separation. Present disclosure also provides a method for manufacturing the hybrid semiconductor transistor structure.