This paper proposes a new type of optic-fiber sensor,which is based o n intermodal interference when a standard single-mode fiber is bendt,and experimentally confirms it can be used in refractive index (RI) measurement and temperature measurement.The sensor has a very simple structure,and the sensing area consists of a semicircle standard single-mode fiber with a certain bending radius.The radius of bare fib er is classified as 4.5mm.In the band from 1510nm to 1590nm,when the surrounding RI increases from 1.3288to 1.3721,the RI sensitivities of the two response dips are 147.602nm/RIU and 125.459nm/RIU respectively at normal temperature.As well,when the environment temperature changes from 23℃ to 33℃,the temperature sensitivities of the two respo nse dips are －280pm/℃ and －460pm/℃, respectively.But when temperature is less than 23℃,the change of temperature has almost no obvious effect on sensor,so it can realize RI measurement with no influence by temperature at n ormal temperature.