In this papor a number of problems in connection with the polarographic oxygen electrode are discussed.1.The equation of diffusion current for the dissolved oxygen in the body of the electrode has been derived and examined experimentally.2.The sources of the residual current has been analysed and found to be attributed to the orovice involved in Pt-glass border.3.According to the calculation of heat conduction of the system designed by us,the electrode should be independent of temperature.4.A design of the detector is described,theroby the contamination of the working electrode surface by the surface active substances can bo avoided.