Abstract: The plant Thin Cell Layer (TCL) culture system is a novel system developed in early 1970’s. Sensitive to the regulaing factors and easy to use, TCL has been used on the studies of cell division and differentition, mechanism of plant growth and development. The latest progresses and application of TCL in morphogenesis, cytology and molecular biology are reviewed. A brief description is given on problems to be solved in the use of TCL.