The crystal of the complex of 1, 8-naphtho-l6-crown-5 with La(NO₃)₃ belongs to monoclinic system, apace group P2₁/n, with paameters of unit cell a=5.455Å, b=11.512Å,c=13.826Å,β=109.6° and Z=4.The intensity data of observed reflections were collected on the PW-1100 four-circle diff'raotometer with CuK_a radiation.Its structure was determined by heavy-atom method and the coordinates and isotropic temperature factors of all atoms were refined by full-matrix least square method.The final R factor is 0.108.The coordination number of the lanthanum ion is eleven.The five ether oxygena are on ono aide of the La ion with La-O=2.78Å while six ozygena from three bidentate nitrates are on the other aide with La-O=2.59-2.63Å.