The energy spectrum of the measured current velocity near the surface of the South Yellow sea was studied with the modern descriptive statistics. Ihe data cited here were taken from the National Marine Geological Suevey during the years 1975-1977. This paper consists of three main parts: 1) discussion of the stationary stochastic or quasi-stationary random of the measured current velocity; 2 )a method on determinating the time series data length ensured statistically; and 3 )an analysis on the character of the energy spectrum of the measured current velocity near the surface of the South Yellow Sea.