The generation and composition of the monthly data files of radiosonde measurements are briefly introduced. The calculation method of the data processing software for the L band radar observation system in dealing with the radiosonde data，the existing radiosonde measurements，and the functions of quality control software for the monthly data files of radiosonde measurements are disscussed, and it points out that the key to control the quality of monthly data files of radiosonde measurements is the quality control of the original second data of the basic data files of radiosonde measurements (second data file). The second data file is the encoded data of radar signals，and it is necessary to integrate the functions of the quality control software of the monthly data files for radiosonde measurements with the L band radar data processing software. Some typical examples are given. It is pointed out that the existing parameter database for the monthly data files of radiosonde measurements presently used has defects compared with the observational data.