Abstract: Arabidopsis thaliana DSP1（defective in snRNA processing 1） protein is one of the essential member in DSP complex. It is involved in snRNA transcription and maturation and plays vital roles in multiple plant developmental processes. This study has taken advantage of online tools to predict the physical and biochemical properties of DSP1 and its secondary and tertiary structures. Since the attempt of expressing full-length DSP1 protein in bacteria was not successful, instead we were able to express and purify GST-DSP1-N fragment in N-terminus of DSP1 and further developed the polyclonal antibody of DSP1 using purified GST-DSP-N protein. Then a total of 45 candidate proteins were identified as the potential DSP1 interacting proteins by immunoprecipitation assay and liquid chromatography tandem technology. The functional clustering analysis of these candidates suggested that they may function in protein metabolism or nucleic acid binding processes. The study has revealed the future objectives and directions for further investigation of DSP1 functions.