Abstract: Dual-wavelength spectrophotometry was applied to determine the amylose and amylopectin content in lotus root from Hanzhong with iodine as coloring agent. According to the color characteristics of amylose mixed with iodine forming blue mixtures and amylopectin mixed with iodine forming amaranth mixtures, and the determination results of Dual- wavelength spectrophotometry, the determination and reference wavelength of amylose were 511 nm and 582 nm, respectively,Y =0.046 43x＋0.011 67 （r^2=0.998 7）; the determination and reference wavelength of amylopectin were 614 nm and 549 nm, respectively,Y=0.004 6x＋0.002 55（r^2=0.996 8）. The amylose and amylopectin content was different in different varieties of lotus root from Hanzhong, the recovery rate of both amylose and amylopectin ranged from 98.07% to 101.3%. The RSD of stability was 1.95% and 1.85%, and the RSD of precision is 0.26% and 0.11%,respectively. The results showed the method Could accurately analyze the starch in lotus root.