For the quadruple magnets, the harmonic components at reference radius can be used to express the field quality using relative harmonics which is the high harmonics components (order > 2) by 2nd component. Generally speaking, the high harmonics components have negative effects on beam focusing. Therefore, the relative harmonics should be decreased to meet a target value. However, the specific influence of the relative harmonics on beam focusing in three dimensional is difficult to be expressed. In order to estimate the effects of each harmonic component on particle movement, this study presented beam trajectory analysis in three dimensional with respect to harmonic components by SCALA. Frist, magnetic field distribution was obtained from a given quadruple triplet using Fourier analysis. Then, the harmonic components which compose the field inhomogeneity were removed one by one from the total magnetic field of the given quadruple triplet. Several magnetic field distributions with different harmonic components were generated. Therefore, the beam trajectories can be simulated in SCALA with respect to magnetic field harmonic components. The field quality of quadruple magnets can be expressed by the effects of harmonics components on beam focusing.