he effects of rodents to forest dynamics are highlighted in many ecological researches. In 2002 and 2003, a series of experiments were conducted to investigate the predating behavior of rodents to acorns of Quercus aliena var. acuteserrata under 12 different treatments respectively: burnt fully, enwrapped in plastic tapes, dyed with black carbon ink, buried in soil surface, set on different colors of papers, attached with strings, cut into halves and in control. The count numbers of acorns that were left intact, predated in situ or removed away were examined and documented in detail, as well as the ratios of acorns with infestation before predation and after. It was found that: (1) the ratios of acorns with infestation before predation and after were significantly different (p>0.05), suggesting that rodents could detect the infestation of acorns. (2) the effects of rodents predation to acorns could be classified into 4 classes: ① acorns that were simply buried, or set on black paper were not distinguishable from the control, suggesting that rodents don’t respond to the small changes of odor concentration resulted from burying and might be more adapted to the black other than else background. ② Acorns attached with strings, dyed with black ink, cut into halves or set on white/green/red papers were predated in situ with decreased rate and removed away with the same rate in the first day of observation when compared with those of the control, but the removal lasted longer time. The final ratio of removal was increased, and that of predation in situ was decreased, and none was left intact. This might suggest that rodents have higher predating risk expectation to acorns under the change of their status, colors, completeness or background, and adopted a kind of “less predation in situ" strategy. ③ Acorns burnt fully were neither predated in situ nor removed in the first day, but both rates were increased to the peak in the forth or fifth day, and then begun to decline. Consequently, the final ratio of predation in situ and removal decreased greatly with 50% acorns left intact. This suggests that rodents use the “less predation" or “less activities" strategy to respond to substantial change of acorn odor concentration, and, as a result, much more acorns were remained intact. ④ Acorns enwrapped were rarely predated in situ, but the removal remained unchanged at the beginning, then reduced to near zero in the second day, and kept increasing after that until reaching the peak at the fourth day; the final ratio of predation in situ was lower than 5% with none left intact, and therefore, the removal was greatly increased. It is supposed that rodents take the “less predation in situ" strategy under the condition of substantial change in both odor and states of acorns, since the dual change might indicates higher predation risk and causes rodents to predate less in situ. As is proved here that the detection to the predation risk was critical to rodents’ behavior, it is reasonable to suppose that the eyes of rodents could play a much more important role in rodents’ predating behavior than previously expected.