Abstract: The genetics law on the main stem ear length of new line 93(220) was analysised by using quality-quantity traits maximum likelihood method about the quality-quantity model testing, main and little gene effect with estimating variance.The result showed the main stem of long spike wheat new line 93(220) was one typical quality-quantity trait with one main gene and several little gene controlling. There was one pair of recessiveness main gene controlling ear length, which belonged to the adding-dominance hereditary model. F1 representative was part dominance. The recessiveness main gene average effect of increasing ear length was 1.47cm, while the genetic effect of little gene was 2.83cm. The main stem ear length of one with recessiveness main gene was long spike.