Abstract: In order to investigate the effect of environmental temperature on the internal electrical resistance value of standing trees, two standing tree(Larix gmelinii and Populus simonii)specimens were selected and tested using the electrical impedance tomography instrument at different environmental temperatures. Some two-dimensional electrical impedance images of cross section of specimens were then obtained and comparatively analyzed. The electrical resistance value of each point on the cross section was quantitatively examined and the relationship between these values and temperature were discussed. Research results showed that: ① For L. gmelinii, the electrical resistance value of heartwood was lower than that of the sapwood. As temperature decreased, the red area(high resistance region)at sapwood reduced and the blue area(low resistance region)at heartwood increased. For P. simonii, the result was completely opposite. However, the average electrical resistance values for overall cross section increased as temperature decreased. ② There were highly significant exponential regression models between the sample electrical resistance values and temperature(P<0.01)with the correlation coefficients of ≥0.822(L. gmelinii)and ≥0.926(P. simonii). ③ For L. gmelinii, when temperatures were above 0 ℃, the fluctuation of radial resistance value was not obvious, and the maximum difference was 1 236 Ω(at 3.0 ℃). When temperatures were below 0 ℃, it fluctuated greatly, and the maximum difference was 3 299 Ω(-5.0 ℃). There are two troughs and one peak in the middle of the trend line. ④ For P. simonii, the resistance value of each point in the radial direction showed a trend of increase with the decrease of temperature. The resistance value increased initially and then decreased from one edge to the other in the radial direction.