Treatment of the β-diketiminate-supported ytterbium dichloride LYbCl2(THF)2 1 (L = N,N'-bis(2,6-dimethylphenyl)-2,4-pentanediiminate) with 2 equiv of C5H5Na gave rise to the title complex LYb(C5H5)2 2 (C31H35N2Yb, Mr = 608.65), and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/n with a = 14.417(2), b = 10.432(2), c = 18.040(4)(A),β= 95.73(2)°, V = 2699.6(9)(A)3, Dc = 1.498 g/cm3, Z = 4,λ(MoKα) = 0.71073(A), μ = 3.485 mm(1, F(000) = 1220, the final R = 0.0304 and wR = 0.0703 for 3962 observed reflections with I > 2σ(I). In the molecular structure of the title complex, the central metal atom Yb is eight-coordinated by two cyclopentadienyl groups and two nitrogen atoms of β- diketiminate group to form a distorted tetrahedral geometry.