The FvC5SD gene cloned from Flammulina velutipes and introduced into soybean cultivar Shennong 9 by Agrobacterium mediated genetic transformation of soybean cotyledon nodes, and the transgenic soybean FvC5SD-L05 events showed good drought tolerance and agronomic properties. to clarify the molecular characteristics and detection methods of the transgenic soybean FvC5SD-L05 material for its biosafety evaluation, we analyzed the copy numbers of FvC5SD gene by Southern hybridization and identified the position and direction of the insertion site of foreign gene in soybean genome, basing the 4_^th generation of FvC5SD-L05 events. Meanwhile, by PCR amplifying the left and right flanking sequences of exogenous T-DNA, we also established a specific qualitative PCR detection method for FvC5SD-L05 by its left and right flanking sequences. This method has strong specificity and high sensitivity. It can detect transgenic components in the template with FvC5SD-L05 genomic DNA content of 0.1% and realize the specific detection of FvC5SD-L05 event of stress resistant soybean with FvC5SD gene, which further provides technical basis for the detection and identification of transgenic soybean and its derivatives.