Abstract: Microplastics from plastic debris broken after they entered environment is considered as one of the important sources of microplastics. In this study, plastic films from 5 kinds of packaging bag commonly used in our daily life, including express packing bag, takeaway packing bag, trash bag, bio-based environmentally-friendly bag, and biodegradable plastic bag, were selected to carry out aging-degradation experiment under the natural environment condition. The characteristics of plastic films were analyzed according to tensile test, fourier transform infrared spectrometry (FT-IR) and scanning electron microscope during the experiment period. The elongation-at-break of films from express packing bag and takeaway bag decreased rapidly after 5 weeks of aging period, those from trash bag and biodegradable plastic bag showed a rapid decline at the 2nd week. The mechanical performance testing was not applicable after 7 weeks for the film from trash bag. The elongation-at-break of biodegradable plastic bag varied in a little range during the aging process. The tensile strength of all the films from 5 kinds of packing bag showed a general decreasing trend with increase of exposure time. FT-IR spectra indicated that the aging and degradation products contained carbonyl, vinyl, and hydroxyl group. The index of carbonyl, vinyl, and hydroxyl for the films from the 5 kinds of bag showed an increase trend or an increase-decrease trend with the increase of exposure time, while the index of crystal changed little during the experiment period. At the end of aging exposure experiment, the microstructure of the film from express packing bag and takeaway bag became rough and showed many small pits and cracks. There were many scratches and granules on the surface of film from trash bag, and starch particles peeled from the surface of the film from the bio-based environmental friendly bag. More cracks, potholes, and particle peeling were observed in the surface of film from biodegradable plastic bag. These results provide basic data for the study of environmental behavior processes of packing plastic debris and source of microplastics, assessment of environmental risk, etc.