In order to investigate the influence of sample temperature on the radiation characteristic of laser induced plasma, the target prepared from the national standard soil samples was ablated in air by a Nd∶YAG nanosecond pulse laser with wavelength 1 064 nm under different temperatures (TS≤350 ℃). The line intensity and signal-to-noise ratio of spectrum were measured, the detection limit of analytical spectroscopy and the accuracy of signal measurement were calculated. The experimental results show that, with the increase of sample temperature under the condition of laser energy for 200 mJ, plasma radiation increases and reaches the maximum at the sample temperature of 300 ℃. Calculations show that compared with that of the room temperature, the spectrum line intensities of Al, Mg, Ba and Fe increased by 67%, 58%, 61% and 52% respectively, and the spectral signal-to- noise ratios increased by 41%, 51%, 28% and 38% respectively. The detection limit of analytical elements and the stability of spectral signal were improved. Obviously, the rise of the sample temperature can effectively enhance the quality of the laser spectrum.