A rapid quantification technique is developed and validated for nondestructively quantifying the soluble solids content (SSC) of citrus fruits using Vis/NIR spectroscopy in conjunction with partial least squares regression (PLS) using genetic algorithm (GA). The spectral are recorded in the Vis/NIR region from 350 to 1800 nm using the fiber optic probe method. The navel orange Vis/NIR spectra data are divided into 15 intervals. Consequently, 5 subsets (wave regions 554~643 nm, 1000~1088 nm, 1089~1177 nm, 1445~1533 nm and 1623~1711 nm respectively) and 446 data points are selected quickly by GA-PLS. The best prediction results for the navel orange in predicted set are 0.9132 and 1.2579 for correlation coefficient and root mean square errors of prediction respectively. With the proposed method, a concise easily computed model can be built to select the characteristic region of Vis/NIR spectroscopy.