Cereal starch endosperm is an important source of human staple food, but methods for observing its mature cell structure are very limited. Micro CT technology，a non-destructive three-dimensional imaging technique，is a powerful tool for studying plant morphology. However, due to the uniform density of cereal starch endosperm, conventional micro CT techniques cannot be applied for this case. In this article ten kinds of different cereal seeds were treated by phosphotungstic acid, and dried by CO₂ critical point dryer, according to author’s previous research; then the cell structure of cereal starch endosperm can be clearly distinguished by Micro CT. This paper provides a new method for micro CT scanning of cereal starch endosperm cells.