The red swamp crayfish Procambarus clarkii is one of the global invasive species and has caused huge damage to aquaculture, biodiversity and ecology in the world. Antennal-expressed receptors are important for P. clarkii to detect olfactory cues for mate attraction, et al.. However, few olfactory and chemosensory-related genes were reported in P. clarkii until now. In the present study, we used RNA sequencing to investigate the olfactory and chemosensory-related genes of the antenna of P. clarkii during the non-mating and mating period. A total of 59218 unigenes with an average length of 1056.41 bp, and 4889 differentially expressed unigenes (DEGs) with 2128 up-regulated and 2761 down-regulated unigenes were obtained. Of which, 13 up-regulated and 9 down-regulated DEGs were identified to associated with olfaction and chemical reception, including 4 IRs or iGluRs, 8 G-protein coupled receptor, 5 transient receptor potential channels (TRP channels), 1 sodium-calcium exchanger, 1 olfactory receptor, 1 isomerase and 2 chemosensory proteins (CSPs). CSPs were preliminarily classified into pheromone receptors in male red swamp crayfish. The results of quantitative real-time reverse transcription PCR (RT-qPCR) showed that the expression trends of 8 selected unigenes were consistent, and this result also validated the RNA-Seq data. Our results provide more comprehensive data of olfactory and chemical communication mechanism after crayfish entering the mating period.