To evaluate the risk of Spodoptera frugiperda(S. frugiperda) switching from corn to rice, after 10 generations of successive feeding on corn leaves in the laboratory, the newly hatched S. frugiperda larvae were fed corn and rice, respectively, and the following generations, CnC1 and CnR1, were produced. The CnR1 was fed with rice leaves for 8 generations and then divided into 2 groups. One group continued to feed on rice and reproduced 1 generation(CnR8R1), and the other group fed on corn and reproduced 1 generation(CnR8C1). Then, the duration of larvae in CnC1, CnR1, CnR8R1 and CnR8C1 treatment groups was recorded, the survival rate and fecundity were calculated, and nutritional effect and digestive enzyme activity were also detected. These results indicate that larval duration of CnC1 was the shortest(17.46 d) and of CnR1 was the longest(23.24 d), with significant difference between the two groups. The survival rate of CnR1 was significantly lower than those of other treatments. CnC1 group had the most eggs laid per female(693 eggs), whereas CnR1 had the fewest eggs laid per female(384 eggs). Additionally, the relative consumption rate of CnR1 and CnR8R1 larvae was significantly lower than those of CnC1 and CnR8C1. The efficiency of conversion of ingested and digested food of larvae showed no significant difference among the four treatment groups. There was significant difference in pepsin activity of larval midgut during host transition period, but there were no significant difference in lipase and amylase activities. Therefore, it was determined that the population growth rate on corn was unaffected when the population on rice was host re-switching to corn, based on larval survival rate, fecundity, nutritional effect and digestive enzyme activity. Although rice is not the most suitable host for S. frugiperda, it still has the potential to adapt to feeding on and damaging rice after it switched from corn to rice.