To make a detailed test on the reliability and detection performance of the electrochemical concentration cell (ECC) type ozonesonde which had been developed and preliminarily evaluated by the authors, an intensive ozonesonde release experiment was held at two sites in Beijing and Changchun in June 2013. The results showed that the mean background current and its standard deviation were 0.03 (0.04) μA and 0.02 (0.03) μA in Beijing (Changchun). The average response time and its standard deviation were 27.8 s (30.4 s) and 4.0 s (3.7 s) in Beijing (Changchun). The ozone partial pressure profiles at both sites showed a central peak in the stratosphere and a side peak in the boundary layer. Large variation in ozone partial pressure was observed at the middle levels of the atmosphere (10–17 km). A more marked gradient of ozone change was observed in Beijing (3.4 mPa km–1) at the lower atmosphere level, as compared to that in Changchun (0.4 mPa km–1). The results presented in this paper indicate that this self-developed ozonesonde shows a high level of reliability and good performance. The ozonsonde is expected to play an important role in operational observations of ozone profiles.