This paper presents an untrimmed stable CMOS Nano-Ampere current reference over a wide temperature range with curvature-compensation scheme which is realized by utility self-biased CMOS β-multiplier circuit and operating near to zero-temperature coefficient of MOSFET. Besides, analysis of the proposed circuit is illustrated. The current reference is 142.5 nA with temperature coefficient (TC) of 40 ppm/ °C over a temperature range from -40 °C to 85 °C and the line sensitivity is 1.45%/V in a range of supply voltage from 1.2 V to 2 V. The proposed current reference consumes a silicon area of 0.02 mm 2 and simulation results of the post-layout reveal that the current reference and the TC are deviated by 0.2 nA and 0.69 ppm/°C, respectively. The proposed circuit is designed and taped-out in 0.18 μm CMOS technology with single supply voltage of 1.8 V.