The data presented in this paper are related to the research article entitled "Transcriptome profiling of developing spleen tissue and discovery of immune-related genes in grass carp (Ctenopharyngodon idella)" (Li et al. 2016) [1]. Please refer to this article for interpretation of the data. Data provided in this submission are comprised of the expression levels of unigenes, significantly differentially expressed genes(DEGs), significant enrichment GO term and KEGG pathway of DEGs, and information of the transcripts assigned to six immune pathways.