Residual ozone Ωres is the integrated column ozone from the balloon bursting altitude, which is generally from 30~5hPa, to the top of atmosphere. The ozonesonde correction factor Cref is the ratio of total column ozone Ω, which is precisely observed by ground or spacebased spectrophotometer, to the summery of Ωecc and Ωres. Ωecc is the integrated ozonesonde data from ground to the balloon bursting altitude. Cref is applied to assess and correct the stratospheric ozonesonde data with the well qualified Ω. Based on the sporadic Electrochemical Concentration Cell (ECC) ozonesonde data observed at different sites of China, Ωres deduced by the Constant Mixing Ratio (CMR) and satellite zonal mean (including SBUV and MLS tables) are presented, and the impact of Ωres on Cref is investigated. The contributions of ozone vertical distribution to Cref are also analyzed, and appropriate method to quantify Ωres is proposed through the Cref comparisons. Ωres deduced by CMR method is sensitive to the balloon-bursting altitude, and is frequently overestimated. As a result, Cref is generally less than 100%. Ωres deduced by the satellite zonal mean method is not sensitive to the balloon-bursting altitude. However, Cref is lower than about -10DU in two regions. One region is in east of China, such as Longfengshan in Heilongjiang province and Beijing, which is high total column ozone; the other region is Tibetan plateau and other low latitude districts including Hong Kong, which is low column ozone. The satellite zonally underestimated Ωres reflects the longitude dependence of real atmospheric ozone over China. The tropospheric column ozone Ωtro from the surface to 100hPa, stratospheric column ozone Ωstr from 100 to 10hpa and Ωres to Cref account 16%±3.4%, 65%±2.3%, 19%±3.3%, respectively. Therefore, it is necessary to consider the effects from Ωtro and Ωres on the evaluation or correction stratospheric ozone measured by ozonesonde if Cref is used. The satellite zonal mean method is generally recommended, especially the Ωres obtained when it is very close to the quasi real-time SBUV data. However, as the balloon bursting altitude above 10hPa, the conventional CMR method is also recommended for the two regions including north of east and north in China (winter and summer)-the high total ozone region, and Hong Kong (summer, autumn and winter), Tibetan plateau (summer) -the low total ozone region. It can weaken a system underestimation of Cref if the satellite deduced Ωres is used.