With the development of sensing technology,the application of sensors has been m uch broader.High precision temperature sensors are needed in plenty of occasions and the interferometric optical fiber sensors have been widespread concerned be cause of some advantages such as high sensitivity,anti-electromagnetic interfer ence and so on.Therefore,a sensor with tapered single mode fiber thin code fiber spherical structure (tapered-SMF-TCF-spherical structure) structure is propo sed based on compound interference principle.This sensor is fabricated by inserting a single mode fiber as well as a thin-core fiber,which are of the sam e length,between a tape red structure and a spherical structure,As temperature changes,the phase differe nce between the core mode and the cladding mode changes,resulting in shifts of t he dips in the transmission spectra.By measuring the shifts of dips,the temperat ure variation can be obtained,the realizing temperature sensing.The temperature experiment shows that when the temperature changes from 30℃ to 75℃,the two dips in transmission spectra move 1.5nm and 3.75nm toward the long wavelength respectivel y,and the sensitivities are 0.033nm/℃ and 0.083nm/℃.The proposed sensor is c haracterized by small size,easy fabrication and low cost,and the temperature sen sitivity of two dips is high,thus having a good prospect in double or multiple parameters measurement.