This experiment was made on the emission spectrochemical analysis for determination of mineral constituents of ash in forest and garden tree-leaves. The sample trees are shown in Table I; fiteen kinds in all, that is, five kinds from each of coniferous, ever green and deciduous brode leaves trees, and the number of sample trees is three in each kind. (1)The ratio of ash are notably different between the kinds of trees, but the difference is not very great between the living forms of trees such as coniferous, ever green and deciduous brode leaves trees. (2)The coefficient of variation of spectrochemical analysis is different from element to elements, but in this experiments, the results of testing these methods show that the error Percentage is below adout 30 per cent. (3)In this experiment we determined nine elements in the mineral constituents of ash in forest and garden tree-leaves, and the results are as follows: The contents of Ca, Mg, Al, B, Fe in conifer, Ca, P, Si, B, Fe in ever green, and Ca, Si, B, in deciduous brode leaves trees increased with ash ratios, but Mn, Cu in conifer and ever green brode leaves trees, and Mg, Al, Fe, Cu in deciduous brode leaves trees have nothing to do with ash ratios. This seems to be connected with Si content in ash of tree-leaves.