The work aims to determinate the content of erucamide in low density polyethylene and study the stability of erucamide after ultraviolet radiation and high temperature treatment. The erucamide was extracted from the xylene dissolving films after several procedures like centrifugation, nitrogen blowing and methanol re-dissolving, and its content was measured by high performance liquid chromatography. The erucamide was subject to ultraviolet radiation and high temperature treatment. The stability of standard erucamide was studied by HPLC, gas chromatography-mass spectrometry and Fourier transform infrared spectroscopy. The erucamide had good linearity in the range of 2~100 µg/mL with a correlation coefficient R>0.999. The detection limit and the limit of quantitation of the method were 0.6 µg/mL and 2 µg/mL, respectively. The added recovery was at 98.6%~112.3% and the relative standard deviation was at 5.6%~8.6%. No new chemical bond was found in the erucamide after ultraviolet radiation and high temperature treatment, and the content of erucamide was not significantly reduced, either. Determination of erucamide by means of HPLC has good stability and sensitivity. After high temperature treatment and ultraviolet radiation, the erucamide is more stable and chemical reactions like degradation hardly occur.