Abstract: Chitosan film (CSF) loaded with cinnamaldehyde (CI) for antimicrobial packaging was prepared using supercritical solution impregnation (SSI). The effects of impregnation pressure and depressurization rate on loading capacity (LC) of CI-CSF were investigated,and the properties of CI-CSF were characterized such as morphology,water vapor permeability (WVP),opacity and antibacterial tests. The results showed that LC of CI-CSF decreased with the raise of the depressurization rate,and the maximum LC achieved to 2.44% at 15 MPa and 1 MPa/min. After the SSI process,the WVP of CI-CSF increased from 0.96×10^-10 g·m^-1·s^-1·Pa^-1 to 2.72×10^-10 g·m^-1·s^-1·Pa^-1 while the opacity of CI-CSF increased from 1.31 to 4.59 mm^-1.CI-CSF showed good antibacterial activity against Staphlycoccus aureus and E.coli. with inhibition zones of 17.3 and 16.0 mm,respectively. The cinnamaldehyde loaded chitosan film prepared using supercritical solution impregnation process was promising for potential application in active food packaging.