Abstract: The lanthanid-organic coordination polymers of {[Ln(H_2O) _2(O_2CCH_2CH_2CO_2) _3]·H_2O}_n (Ln= Eu(Ⅲ),Sm(Ⅲ)) were synthesized by solvent-thermal methld.The crystal structures were characterized by X-ray diffraction method and FT-IR spectrophotometer.The result indicate that both coordination polymers belong to monoclinic, space group C2/c, with cell parameters of Eu coordination polymer 1:a= 2.000(04) nm,b=0.7780(02) nm,c=1.387(03) nm,α=90 °,β=121.58(3) °,γ=90 °,V＝1.838(66) nm~3,Z＝4,F(000)=1344,M_r= 706.18, D_c= 2.551 Mg/m~3, μ=6.839 mm~(-1), R_1=0.0357, ωR_2=0.1012;with cell parameters of Sm coordination polymer 2 is a =2.0072(02) nm,b=0.7822(26) nm,c=1.3901(61) nm,α=90°,β =121.5840 °,γ=90 °,V＝1.8593(3) nm~3,Z＝4,F(000)=1336, M_r= 70296, D_c=2.511 Mg/m~3,μ=6.333 mm~(-1), R_1=0.0210,ωR_2=0.0498. Fluorescence properties had been observed in F-4500 FL spectrophotometer.