This research was designed to determine the pyrolysis kinetic parameters of HDPE using Peak Property Method (PPM) which was recently developed. The properness of PPM was verified by comparing theoretical Derivative Thermogravimetry (DTG) curve with experimental one. The kinetic parameters derived from PPM was compared with those estimated from typical analysis methods and those reported by previous studies. The PPM was developed based on the assumption that a specific pyrolysis reaction would be characterized by three peak properties of DTG curve: peak temperature, peak height, and conversion at peak temperature. The activation energy, pre-exponential factor, and reaction order of HDPE pyrolysis reaction, respectively, were 251.92 kJ/mol, 1.70 × 10¹⁷ min^-1, and 0.581, demonstrating good agreement with those estimated by DTG curve fitting method[1]. The PPM simulates experimental DTG curve excellently and it was proved that the three peak properties of DTG curve would be enough to represent a unique thermal reaction. The pyrolysis kinetic parameters would be estimated easily but accurately by the PPM. However, the PPM is only applicable for a reaction which is represented by a conversion function of power law equation.