Abstract: The induced resistance of the glucohexaose to tobacco mosaic virus (TMV) was investigated by method of greenhouse trials and (Fab’)2-ELISA. The results indicated that the efficacy of the induced resistance of the glucohexaose varied with the concentration in the range of 1~10 μg/mL, the optimum for the highest efficacy was 10 μg/mL. It was also found that the best lag period of the induced resistance of glucohexaose was 7 d and the protection period was about 28 d. On the other hand, with the increasing of spraying times, the higher efficacy of the induced resistance to TMV appeared.