In order to promote efficient production of aromatic hydrocarbons, catalytic co-pyrolysis of corn stalk and high density polyethylene (HDPE) over HZSM-5 zeolite catalyst was performed using quantitative Py-GC/MS. For the catalytic fast pyrolysis (CFP) of HDPE, the relative content of aromatic hydrocarbons tended to increase at first and then decreased gradually. For the catalytic co-pyrolysis (co-CFP) of biomass and HDPE, the effects of co-CFP temperature and mass ratio of biomass to HDPE (biomass/HDPE ratio) on the relative content and economic potential of aromatic hydrocarbons were investigated, and the experimental results showed that the highest relative content of aromatic hydrocarbons was obtained at the temperature of 500-600 degrees C, whereas 700 degrees C was optimal when the yield of total organic pyrolysis products was taken into account. In addition, the relative contents and value index (VI) of target products remained virtually constant when the biomass/HDPE ratio was > 1:1, but then increased with decreasing biomass/HDPE ratio when this mass ratio was < 1:1. The hydrogen to carbon effective ratio (H/C-eff ratio) of feedstock should be adjusted to be > 1.0 so that high relative contents and VI of aromatic hydrocarbons could be achieved. (C) 2014 Elsevier Ltd. All rights reserved.