The self-cascode (SC) structure has low output voltage swing and high output resistance. In order to implement a simple and better SC structure, the native-Vth MOSFETs which has low threshold voltage (Vth) is applied. The proposed SC structure is designed using a qualified industry standard 0.18-㎛ CMOS technology. Measurement results show that the proposed SC structure has higher transconductance as well as output resistance than single MOSFET. In addition, analog building blocks (e.g. current mirror, basic amplifier circuits) with the proposed SC structure are investigated using by Cadence Spectre simulator. Simulation results show improved electrical performances.