Abstract: Quality analysis on the vertical distribution data observed by the Chinese-made ozone sonde system over Beijing from April 2001 to September 2004 is presented.The basic parameters observed by the system including the temperature of electronic chemistry cell in the sonde, the maximum of atmospheric ozone partial pressure and its altitude, the temperature and altitude of tropopause indicate that the stability of the sonde system needs to be improved.The integrated column ozone from the sonde system is generally higher than that of observed by the ground-based Dobson spectrophotometer, and the difference of them is with-in ±20% from 2002 to 2003.11 times simultaneous comparison measurement s show that the ozone partial pressure below 15 km and in 25～30 km observed by Chinese-made ozonde sonde system are higher than that observed by the ECC ozone sonde system with double cells which is extensively used.Also, the result suggests that the Chinese-made ozone sonde system participate the international calibration campaign organized by the Global Atmospheric Watch World Meteorological Organization(GAW/WMO).Wi th the certain technological availability, the single cell in Chinese-made ozone sonde system is recommenede to be updated by double cells.