Abstract:The appropriate values of different apple varieties’ leaf nutrient elements in different areas are diverse, determination of the standard for apple leaf nutrients has guiding significance for nutrient management. The leaf nutritional element contents of Delicious apple in Gansu province were studied. The results show that the variation patterns of constant nutrition elements are smaller than those of trace elements. The contents of N, P, Ca, Mg, Zn and Mn of high yield orchards are significantly higher than those of low yield orchards, while the iron contents of high yield orchards are significantly lower than those of low yield orchards and the middle yield orchards. The K and B contents are not significant in difference orchards. According to the results of X2 test, the distributions of the N, P, K, Ca, Mg and B contents in leaves are in the normal distributions, while the contents of Cu, Fe, Mn, and Zn are in skewed distributions (X2 distribution). According to the probability classification method, the values of normally distributed characters could be divided into 5 grades which correspond to the absence values, low values, normal values, high values, and excess values of standard range of nutritional elements, and the occurrence probabilities of 1-5 grades are 10%, 20%, 40%, 20% and 10% respective1y. The values from(X-0.5246S)to(X+0.5246S)could be the normal values of the standard ranges which are close to the average values of leaf nutritional elements in high yield orchards. The values of X2 distributed characters could be corrected by the average values of leaf nutritional elements in high yield orchards. In view of the above, compared with the other standards, the standard ranges of apple leaf nutritional elements of delicious apple in Gansu province are that the characteristics of N, P, K, Mn, Zn, B are normal, Ca, Mg, Cu are higher, and Fe is highest.