Observations of the temperature and salinity microstructures with Mark-III CTD microprofiler were carried out by Institute of Oceanology, Academia Sinica in September 1985, along an oblique section through the Huanghai Cold Water Mass, the Qingdao Water Mass, and near by the Southern Huanghai Warm Current Water in the South Yellow Sea. In this paper, hydrological conditions along the section, including temperature T, Salinity S, conditional density σt Brunt-V?is?l? frequence N, geostrnphic current V, Richardson number Ri and so on are separately analysed according to the data obtained with Mark-III CTD. Microstructures of temperature and salinity along the oblique section are apparent and rich. Statistic characteristics of the temperature and salinity gradient layers, including the intension, thickness, and depth of upper and lower boundary of the gradient layers are represented in histogram and discussed. In addition, statistical parameters of the gradient layers such as the mean value, the mean-square deviation, the skewness S, and the kurtesis K are also calculated and analysed.