We report what we believe to be the first demonstration of the second and third harmonics in tellurite microstructured fibers pumped by a $1557\mathrm{nm}$ femtosecond fiber laser. The intensities of the second and third harmonics are enhanced by increasing the nonlinear coefficient of the tellurite microstructured fiber. By using tellurite microstructured fiber with a core diameter of $\approx 2.7\mu \mathrm{m}$ , supercontinuum light expanding from $470\mathrm{nm}\text{to}2400\mathrm{nm}$ could be achieved. The effects of the fiber-core diameter on the flatness of the supercontinuum light are also investigated when pumped at $1557\mathrm{nm}$ .