The temperature structure function C2T(h)(r1=0.5 m, r2=1 m) and power-law exponent α(h) of the temperature fluctuation spectrum as functions of altitude are obtained by a novel thermosonde. The thermosonde provides two-channels for micro-thermal probes in different configurations. This arrangement can not only measure temperature, humidity, pressure, wind speed and direction, refractive index structure constant profile, Fried parameter, seeing, isoplanatic angle, coherence time, but also provide power-law exponent profile of the temperature fluctuation spectrum. It is found the difference between α(h) and Zilberman′s three-layer model in the free troposphere. These results are useful for optical propagations, optical communications, remote sensing and numerical models of atmospheric turbulence.