This paper presents a novel RFID tag chip with temperature sensor in 0.18μm standard CMOS process. It consists of four blocks: RF/analog front-end circuit, 192-bit non-volatile memory (NVM), temperature sensor and digital baseband circuit. A CMOS UHF rectifier with dynamic bias using switch capacitor is proposed to improve the efficiency of rectification, while avoiding using costly Schottky diodes. We design a 192-bit NVM in standard CMOS process based on FN tunneling phenomenon with extremely small current density. It dissipates only 1.8μW/3.6μW for reading/writing operation. A 0.8μW smart temperature sensor with ±1 o C resolution without power hungry ADCs is achieved. As a result, the power consumption is 5.8μW, 6.8μW, and 8.6μW for reading sensor, reading NVM and writing NVM respectively. The chip core area is 0.6mm 2 in 0.18μm CMOS process.