Abstract: Leaf number on main stem of wheat is an important sign of growth and develop-ment age. The difference of thermo-photoperiod reaction among verieties is reflectednot only in ear development and heading date, but also in leaf number on main stem.The result showes that heredity and thermo-photoperiod c

Key words: Wheat （Triticum aestium L.）, Leaf number on main stem, Thermophotoperiod development