Abstract：Graphitic carbon nitride supported palladium catalysts were prepared by photo-deposition method (Pd/g-C3N4-PD) and impregnation method (Pd/g-C3N4-IMP), respectively. The as-prepared catalysts were characterized by inductively coupled plasma-atomic emission spectrometry (ICP-AES), x-ray diffraction (XRD), transmission electron microscopy (TEM) and zeta potential measurement. The isoelectric points (IEPs) of Pd/g-C3N4-PD with different palladium load were around 2.3. The metallic Pd particles were uniformly dispersed on the surface of Pd/g-C3N4-PD catalyst, and the average Pd particle size on Pd/g-C3N4-PD was smaller than that of Pd/g-C3N4-IMP. Both Pd/g-C3N4-PD and Pd/g-C3N4-IMP catalysts were used in the liquid phase catalytic hydrodechlorination of 2,4-dichlorophenol. Results showed that Pd/g-C3N4-PD exhibited significantly higher catalytic activity than Pd/g-C3N4-IMP. Low pH was beneficial to the catalytic hydrodechlorination of 2,4-dichlorophenol, however, it did not benefit stability of catalyst.