[Objectives]  To investigate the transcriptional response of Knickkopf family genes to 20-hydroxyecdysone in Locusta migratoria in order to advance research on the function of LmKnk family genes, and lay a foundation for further research on the regulation of the transcription of genes involved in cuticle development in L. migratoria. [Methods]  RT-qPCR was used to analyze the expression characteristics of four LmKnk genes in the integument of L. migratoria from 1-day-old fifth-instar nymphs to 3-days-old adults. 20E was then injected into nymphs to analyze the expression of LmKnk family genes and RNAi was used to suppress the expression of the 20E receptor gene LmEcR and thereby detect transcriptional changes in LmKnk family genes. [Results]  RT-qPCR revealed that LmKnk was evenly distributed in the integument of 1-day-old fifth-instar nymphs to 3-days-old adults, and that the expression of LmKnk2, LmKnk3-FL and LmKnk3-5¢ all gradually increased before molting but decreased rapidly after molting. Each of the LmKnk family genes responded to 20E at a different time point. Expression of LmKnk and LmKnk2 rapidly increased 3 and 6 hours after 20E injection, respectively, whereas expression of LmKnk3-FL and LmKnk3-5¢ was upregulated 12 hours after 20E injection. dsLmEcR injection reduced transcription of all four LmKnk family genes in 1-day-old fifth-instar nymphs. [Conclusion]  LmKnk family genes are downstream genes that can be regulated by 20E in L. migratoria.