Abstarct: Today, with the advancement of technology, the need for voltage reference circuits with low power consumption and high accuracy is felt in most electronic devices. These voltage references are one of the basic building blocks used in many analog circuits such as data converters, sensors, and regulators. The proper design of a voltage reference depends on several factors, including temperature coefficient, line sensitivity, power consumption, and small circuit dimensions. Due to the fact that nowadays in IoT and medical applications, most of the electronic devices are made in small dimensions and should be light and portable, for this reason they use small batteries with a lower capacity and we need the circuits of such devices to have low power consumption. In this thesis, a sub-1V voltage reference with picowatt power consumption has been designed and simulated. All its transistors are designed in the sub-threshold region and use the DIBL effect to have smooth coefficient consumption and low line adjustment. In this design, only four transistors (thick oxide, native VTH and medium VTH) are used, and the body of all these transistors is connected to their source. To check the performance of the proposed voltage reference and its dependence on the three important factors of temperature, power supply and manufacturing process, the proposed circuit was designed and simulated in standard CMOS technology of 0.18 μm in Cadence Virtuoso and has a TC of 7.699 ppm/° C is in all process corners and in the range of 0 to 100 °C. The line sensivity value of this circuit in the voltage range of 0.6 to 3.3 volts is about 0.029%/V. The output voltage of this proposed circuit is 341.609mV and has a power consumption of 249.3pW, which is for IoT applications. This proposed circuit has 0.017mm2 active area.