A high DC gain self-cascode structure of operational transconductance amplifier (OTA) design with bandwidth enhancement is proposed. Based on the concept of self-cascode structure, which provides high output resistance and transconductance, the proposed OTA presents a compensation methodology to obtain better unity-gain bandwidth. The proposed OTA is compared with previous structures, with the same size of input/output transistors and compensation capacitance as well as load capacitance, and simulation results show a DC gain enhancement of >20% and 2.4 times unity-gain bandwidth at the same time, and the performances of the proposed OTA bring a better figure of merit (FOM).