I have been working as Professor of mathematics in the College of Mathematics and Information Science, Hebei University since 1987. Meanwhile, I was Visiting Professor at the Department of Mathematics and Statistics, Curtin University, Australia, for different durations from 2002 to 2016, and was also visiting research fellows at The Hong Kong Polytechnic University, Hongkong, in 2003 and at the Department of Mathematics, Mahidol University of THAILAND, Thailand, in 2007. My main research areas include Ordinary differential equation, Functional differential equation, Impulsive differential systems and Dynamic equations on Time Scale. I have published more than 150 referee’s papers in international journals.