To provide a scientific basis for control measures of the third-generation armyworm Mythimna separate（Walker） in Jilin Province, this study aimed to prove the feasibility for scanning entomological radar prediction onthe second-generation armyworm. The results showed that the number of radar echo was high at 8 PM and 9 PM dur-ing the peak period of the second-generation armyworm. There was an inverse relationship correlation between ra-dar echo and elevation. There was a positive correlation between number of the armyworm observed in trap, verticalpointing searchlight and the sum echo of elevation 3°, 5°, 8° and 12°. The result can be an effective data index forthe second-generation armyworm prediction.