The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae) is one of the most serious pests of cruciferous vegetables and has developed resistance to many kinds of insecticides, including abamectin. Abamectin is a neurotoxin that can directly activate or potentiate glutamate-gated chloride channels (GluCls). In the present study, four GluCl variants of P. xylostella (PxGluCl-A, PxGluCl-B, PxGluCl-C and PxGluCl-D) generated by alternative splicing of exons 8, 9 and 10 were identified in a field P. xylostella strain that showed 1389.7-fold resistance to abamectin. Electrophysiological analysis using Xenopus laevis oocytes showed that compared to the original PxGluCl, the PxGluCl-A channel (formed by alternative splicing of exon 8), PxGluCl-B and PxGluCl-C channels (both formed by alternative splicing of exon 9) and PxGluCl-D channel (formed by alternative splicing of exon 10) showed reduced sensitivity to glutamate and abamectin. In addition, the heteromeric channels formed by the combination of the four splice variants also demonstrated significantly reduced sensitivity to glutamate and abamectin except PxGluCl-(B+C), which showed less sensitivity to abamectin but not to glutamate. In contrast, the responses of all the homomeric and heteromeric channels to fipronil were similar to that of the original PxGluCl. These results showed that the expression of four PxGluCl splice variants may be involved in abamectin resistance. Our findings lay a foundation for further investigating the mechanisms of abamectin resistance as well as the physiological functions of these splice variants in insects.