A new organophosphorus insecticide Shacanlin [O,O,O',O' - tetramethyl - S - S' - (2 - N, N - dimethylamino - trimethylene) - bis - phosphonodithionate] was synthesized and its oxalate was prepared. The crystal structure of Shacanlin oxalate was determined by SRD. The x - ray single crystal structure analysis shows that the crystal is in triclinic space group P 1 and the unit cell parameters as follows: a = 0.74342(%)nm, b=1.1057(4)nm, c = 1.45295(11)nm, α= 98.018(11)°,β = 101.012(4)°,γ= 96.224(10)°,Z = 2. The compound was characterized by elementary analyses, MS、IR and ^1H, ^1^3C NMR.

Key words: CRYSTAL STRUCTURE, ORGANO PHOSPHORUS COMPOUNDS, INSECTICIDES, ELEMENTAL ANALYSIS, INFRARED SPECTROPHOTOMETRY, PROTON MAGNETIC RESONANCE SPECTROMETRY, C13 NMR SPECTROMETRY