The　title　compound　(C5N5H41P2Mo5O30　5)　was　synthesized　under　hydrothermal　condition　and　its　crystal　structure　was　determined　by　X-ray　diffraction.　It　belongs　to　triclinic　system,　space　group　P　(1)　over　bar,　with　a=9.9645(6),　b=10.8666(7),　c=15.814(1)Angstrom,　a=71.482(3),　beta=88.528(2),　gamma=78.448(2)degrees.　V=1589.4(2)Angstrom(3),　D-c=2.510g/cm(3,)　Z=2,　mu=2.138mm(-1),　lambda(MoK　alpha)　=　0.71073　Angstrom,　F(000)=1180.　The　final　R　and　wR　were　0.0396　and　0.1052　for　6626　observed　reflections　with　I　greater　than　or　equal　to　2sigma(I),　respectively.　The　result　of　the　structure　analysis　indicates　that　the　[Mo5O15(PO4)　(HPO4)](5-)　anion　in　the　title　compound　consists　of　five　edge-sharing　or　corner-sharing　MoO6　octahedra　and　two　corner-sharing　PO4　tetrahedra.　Each　MoO6　octahedron　adopts　distorted　octahedral　geometry.