Chinese Sapium sebiferum (L.) Roxb has great potential to emerge as a promising biodiesel resource plant due to abundant oil content in seed. However, the unavailability of transcriptomic and genomic data impedes the progress of application in biodiesel production. Transcriptome analysis will help to further exploit tallow and kernel oil utilization in industry and facilitate molecular-breeding-based genetic improvement of S. sebiferum. Illumina hiseq 2000 sequencing platform was used to perform de novo transcriptome assembly and gene expression analyses of seeds from three strains in three developmental stages. A total of 188,254 unigenes over 200 bp were assembled with average length of 699 bp. These transcriptic unigenes were functionally assigned by GO and KEGG pathways. RPKM was used to identify differentially expressed unigenes of five cDNA libraries. Transcriptic genes endcoding enzymes related to fatty acid metabolism were evaluated. qRT-PCR was employed to confirm five key enzymes involved in fatty acid and triacylglycerol biosynthesis. This study provided comprehensive gene expression information of Chinese S. sebiferum seed at transcriptional level. These tran-scriptome data will facilitate high-oil-content genetic cultivation of S. sebiferum, which will further exploit tallow and kernel oil utilization in biodiesel industry.