High quality single cystal Bi, Gd : YIG films have been grown on GCMZGG wafers by LPE techniques. The magnetic, magneto-optic and sensor properties of the films have been investigated. The films showed high linearity with almost no hystersis, saturaton Faraday rotation angle of 45$^{circ}$, saturation field of about 1.1 kOe, Verdet constant of 5.6$^{circ}$ /(Oe, cm) at room temperature, and temperture coefficient of Verset constant of 0.0056$^{circ}$ /(Oe, cm, $^{circ}C$) in the range of 0 $^{circ}C$~100 $^{circ}C$. The sensor made out of the film exhibited highly linear signal in the range of 3 A-300 A.