In this paper, the thermal degradation kinetics of 2,7-dihydroxynaphthalene (DHN) was presented. The kinetics of the thermal degradation of PDHN was investigated by means of TGA. TG curves showed that the thermal degradation of poly(2,7-dihydroxynaphthalene) (PDHN) took place in two stages. The apparent activation energies of thermal degradation for PDHN, as determined by the Tang method (TM), the Flynn-Wall-Ozawa method (FWO), the Kissinger-Akahira-Sunose method (KAS), and the Coats-Redfern (CR) method were 136.9, 136.2, 140.1 and 143.7 kJ . mol(-1) for the first stage degradation, 99.4, 98.9, 102.6, and 88.7 kJ . mol(1-) for the second stage degradation, respectively. The mechanism function and pre-exponential factor related to each thermal degradation process were also determined by CR method, master plots. The most likely degradation process for each weight loss stages was deceleration type in terms of the CR and master plots results.