The PP micro-perforated films of 40 μm and 50 μm thickness with different number of holes (diameter of 280 μm) in certain distance were prepared. Self-supporting bag was made using the micro-perforated PP film (40 μm) for packing broccoli. Change of gas content and chlorophyll content of broccoli was observed by altering micro-perforation’s position. The experiment results showed that micro-perforation’s position affect the content of O-2 and CO-2; when 2 holes separating by 2cm are punched in the broccoli bud, high O-2 concentration and CO-2 low concentration is produced, content of broccoli’s chlorophyll is highest and broccoli is the freshest. The thickness of micro-perforated self-supporting bag, micro-perforation’s position, perforation diameter and perforation number are important factors influencing gas content in the package when the environmental temperature is certain.