A homoleptic lanthanide guanidinate complex [（CH2）5NC（NiPr）2]3Yb was synthesized by the metathesis reaction of lithium guanidinate with anhydrous YbCl3 in 3∶1 molar ratio in THF.Its crystal structure was determined by X-ray diffraction.The crystallographic data:C36H72N9Yb,Mr=804.07,orthorhombic,space group P212121（#19）,a=10.3168（7）,b=11.443（7）,c=35.5649（2）?,V=4199.1（5）?3,Z=4,Dc=1.272 g/cm3,F（000）=1684.00,T=193.1K,λ（MoKα）=0.7107?,μ=22.61 cm-1,R=0.040,wR=0.126 for 8653 observed reflections with（I>3.00 σ（I））.The ytterbium is six-coordinate by six nitrogen atoms of three chelation bidentate guanidinate ligands.
