The concentration of the element in a sample may be measured by the determination of the spectral line intensity of the element, because the line intensity of the element is affected by the concentration of the element in the sample. The actual determination of line intensity can be made by a visual comparison or an electrical measurement of the persistent line of the unknown sample by means of a series of photographs of the persistent lines of the known concentrations of the element. To accomplish this determination, it is usual to use an internal standard line. In this study, Sn and C lines have been used as control or internal standard for quantitative analysis of the samples of woods, trees and soils to be examined. It seems that if the powdered samples are changed to solutions, C lines may better be used as the internal standard lines than Sn lines; still, it is necessary to improve the accuracy of the method taking the following factors into consideration: (1). The preparation of standard and unkown samples. (2). The loss of the samples from the spark. (3). The penetration of solution into the carbon electrode.