An aerosol time-of-flight laser mass spectrometry(ATOFLMS)had been designed in our lab. ATOFLMS is a technique that can be used to determine the physical and chemical characteristics of individual aerosol particles in real time. It is a powerful tool for researching and monitoring of atmospheric aerosol particles. ATOFLMS generates large amount of data during the process period. How to process these data and extract valuable information is one of the key problems for the ATOFLMS. We developed application software for it based on object oriented programming method. The application software can perform automatically to acquire,process and store the data of size and resolve chemical composition of individual aerosol particles in real time.