【Objective】 To understand soybean pods and multigrain gene regulation mechanisms of improving soybean production, a soybean flower bud cDNA library was constructed. The quality of library construction was initially identified according to the requirements. 【Method】In order to study the novel genes from flower bud mutants of soybean, a full-length cDNA library from flower bud mutants of soybean Jinong 18 was constructed. Total RNA from young flower bud mutants of soybean was extracted. Double strand cDNA was synthesized by SMART method. After proteinase K digestion and SfiⅠ digestion, the ds cDNA fragments were ligated to the λTriplEx vector. A cDNA library of soybean was successfully constructed. 【Result and conclusion】With the unamplified library stored after amplification, the titer of the amplified library was estimated as 2.13×10⁸ pfu/mL and the recombination rate was approximately 95.3%. PCR results showed that the inserts varied from 0.5 to 2.0 kb with an average size of 1.0 kb or so. It indicated that this library could be used for full length genes screening and cloning of low abundance genes. The library will lay a foundation for the genes clon and molecular biological research.