YCa<sub>4</sub>O(BO<sub>3</sub>)<sub>3</sub> (YCOB) was found to have a large temperature bandwidth in XZ optical principal plane. By considering the thermal rotation effect, the temperature bandwidth in spatial directions were studied by theoretical derivation and frequency doubling experiments. The temperature bandwidth in maximum effective nonlinear optical coefficient (<i>d</i><sub>eff)</sub> direction was not as big as that in (30.8°, 180°) direction. The light propagate in the second quadrant was found to have bigger temperature bandwidth than the first quadrant. And the temperature bandwidth was found to change as the wavelength change of fundamental frequency light.