Hydraulic architecture characteristics of plants are usually expressed by such parameters as hydraulic conductivity(Kh),specific conductivity(Ks),leaf specific conductivity (LSC) and Huber value(Hv) and so on. In this article, Hydraulic architecture characteristical parameters of camphor seedlings (Cinnamomum camphora (L.) Presl) which is the important tree species in Karst afforestation was measured and analyzed by a“flushing method” with four treatments (i.e. three intensity of soil drought stress treatments and control treatment in greenhouse). Each treatment had 20 repeated samples. The result showed that the Kh, Ks, LSC and Hv was affected by the stem segment diameter both non-stress and drought stress condition. The relationship between the index and the diameter was positive correlation, and could be described in different functions. The hydraulic conductivity, specific conductivity and leaf specific conductivity of camphor seedlings evidently decreased with increase of intensity of drought stress. However, change of Huber value was not significant under different drought stress. These results indicate that the transmit efficiency of branch with wider diameter provided less pressure gradient than the thinner branch was obviously higher than that of the thinner branch.