Abstract: This article reviews the ideas developed byProfessor Qian Xuesen (H.S. Tsien) on the technological sciences.Professor Qian views the technological sciences as a vital part of　modern sciences functioning as a bridge between the basic sciences and　engineering. As a strong and persistent promoter of the technological　sciences he has formulated a comprehensive theory for the developmentthe technological sciences. This article contains the following sections, namely, what istechnological sciences; the importance of technological sciences; how do　technological sciences contribute to engineering and other applications;education in the technological sciences; how did Professor Qian set up　and run the Institute of Mechanics; mechanics in China should mainly　follow the route of the technological sciences as charted by Professor　Qian.