Lettuce,namely leaf lettuce,has various kinds of appicated species,whose production area has been greatly expanded in recent years Through the cultivated technology of plant tissue and the fosteration of lettuce by using the totipotency of plant cell,so as to tempt the callus organism,and the shoot growth situation can be observed Through the orthogonal experimental design ,we can know the influence caused by different fosteration of chemical element and hormone to the lettuce shoots and compare the mediums of the beautiful hormone combination of the lettuce This experiment use the scientific orthogonal design to choose the best medium ,so as to provide reference data to relevant foundamental search and production This experiment also takes the American leaf lettuce as materials(Lactuca,Sativa,VLongifolia),basic medium ,BA,AgNo3,and NAA as experiment primier Each factor has three concentration levels and takes the value-added coefficients of different mediums as determinated Througgh L9(34) orthogonal design ,we can choose out the medium formula is 1/2MS+AgNo3 4mg/L+NAA 2mg/L which is best suit for the lettuce shoot callus。