Abstract: Observation refers to a psychological phenomenon in which people make a comprehensive and in-depth investigation of things or phenomena around them and determine their nature and relationship according to their true colors. The observation ability in mathematics teaching is to consciously perceive the quantity and shape characteristics of things, that is, to investigate the structural characteristics of mathematical relations, propositions and geometric figures expressed by symbols, letters, numbers or words. This paper expounds how to cultivate students' good observation ability in mathematics teaching activities.