A new furazano(furoxano) energetic compound – 3,4-diaminofurazanofuroxan(DAFF) was first prepared under thermal conditions by losing HCl followed by [4+2] ring-close reaction of 3-amino-4-chloroximinofurazan. Its single crystal was cultivated and X-ray single crystal diffraction, IR and elemental analysis measurement characterized the structure of it. Its crystal is triclinic, space group P 1 with crystal parameters as: a=0.6400(4)nm，b=1.0609(8)nm，c=1.4634(7)nm，=83.53(5)，=87.27(4)，=77.74(5)，V=0.9645(11)nm3，Z=4，Dc=1.737g.cm-3，F(000)=512，μ(Mo K)=0.149mm-1；R1=0.0568，wR2=0.1137。The obtained results indicate that DAFF is not a kind of planar molecule, the three ring-planes twist with the two clamp-angles between them are 27.18（1.99） and 30.48（2.07） .There are hydrogen bonds in molecule and among molecules in crystal.

Key words: energetic compound, furazans(furoxans), 3,4-diaminofurazanofuroxan(DAFF), preparation, crystal structure