In the present work, we obtained the full length sequence of DlDCL gene through longan transcriptome data and analyzed them by means of bioinformatics and realtime quantitative PCR. The purpose is to clarify the expression pattern of DlDCLs in longan somatic embryos and different tissues, as well as their expression profiles responses to hormones and light treatment. The study is help to lay the foundation for the further research on the regulation of DlDCLs genes during longan somatic embryos. The results showed that: (1) there are four members of DCL family genes, i.e. DlDCL1, DlDCL2, DlDCL3 and DlDCL4, and different DlDCLs genes were differentially expressed at somatic embryogenesis stage based on the FPKM value of Unigene. (2) Bioinformatics analysis showed that the physical and chemical properties of the DlDCLs are mostly similar, all of them are hydrophilic and unstable proteins with transmembrane structure and without signal peptide. Meanwhile, there are also some differences: DlDCL2 is basic protein while DlDCL1, DlDCL2 and DlDCL4 are acidic proteins. Subcellular localization prediction showed that DlDCL2 was located in nucleus and chloroplast, while the other three members were located in the nucleus. Protein domain prediction showed that DCLs were highly conserved proteins. (3) Phylogenetic tree analysis showed that the genetic relationship of DlDCLs family in longan were close to those from Citrus sinensis. (4) QPCR analysis showed that the expression patterns of different DlDCLs in nonembryogenic callus (NEC) and somatic embryogenesis (SE) varied a lot, but DlDCLs are relatively high in the stage of embryogenic callus (EC), which may indicated that DlDCLs have distinct but cooperative functions in the process of the NEC and during SE. The expression patterns of DlDCLs in different tissues were also investigated. The results revealed that DlDCL1 and DlDCL2 had the highest expression in the leaf and followed by floral organ tissues, which suggested that DlDCL1 and DlDCL2 may participate in photosynthesis and floral organs development. Moreover, DlDCLs expression was induced by light quality and the concentrations of 2,4D, MeJA, SA, indicating that the DlDCLs signaling pathway might be regulated by several kinds of hormones and light.