Li Yanda, Professor of the Department of Automation. Academician of the Chinese Academy of Sciences. Specialist in signal processing and intelligent control. Graduated from the Dept. of Automatic control, Tsinghua University in 1959. Dean of the School of Information Science Technology, Tsinghua university. He has been mainly engaged in the theory of Signal processing and the method of seismic data processing and discrimination. He proposed a new method for time delay estimation using signal reconstruction with phase function only and a new theorem of signal reconstruction, which made required points reduce from N/2 to N/6.He also proposed a new algorithm, which reconstructed minimum phase signal from its amplitude spectrum only, and a theorem of projective relation for the image reconstruction from in complete projection. In order to apply signal processing and pattern recognition technologies to seismic data processing and discrimination, he presented a new method to improve the resolution of seismic section by means of well-log data and a method for high resolution velocity spectrum estimation. Those methods have been used in Shengli Oil Field and other oil field successfully. He has published over 80 papers, and two books.