SQUAMOSA promoterbinding protein like (SPL) gene family plays an important regulatory role in floral transition and flower development. In this study, we used bioinformatics method to identify 15 CsSPLs with SBP conserved domain from the whole genome of Citrus sinensis, and the relative expression specificity in flower buds and leaves in C. sinensis of different flowering and varieties by using qRTPCR method, which laid a foundation for further exploring the function of CsSPLs during flowering induction. The results show that: (1) these genes distributed on 6 chromosomes and they were named CsSPL1-CsSPL15. (2) Analysis of physicochemical properties showed that the length of the CsSPLs proteins ranged from 130 to 1 075 aa with molecular mass of 14.73 to 118.75 kD. Phylogenetic analysis showed that 15 CsSPLs were divided into 8 subfamilies, and most CsSPLs were clustered with AtSPLs, except for CsSPL4. (3) The predictive analysis of cisacting elements showed that CsSPLs promoter contained a large number of light responsiveness elements, indicating that they might play an important role in the regulation of C. sinensis. (4) Transcriptome data analysis showed that CsSPLs expressed in callus, flowers, leaves and fruits of C. sinensis. The expression of CsSPL3, CsSPL4, CsSPL7, CsSPL8, CsSPL12, CsSPL13, CsSPL14 and CsSPL15 were high in flowers and leaves. (5) The qRTPCR results showed that the relative expression levels of CsSPLs were significantly upregulated in flower buds and leaves of two C. sinensis varieties. And CsSPLs in ‘Gannan Zao’ cultivars were higher than that in flower buds and leaves of ‘Newhall’ cultivars at 5 sampling time points. These results showed that the high expression of CsSPLs in flower buds and leaves led to the early flowering of C. sinensis.