Abstract: Based on the general principle of Atomic and Molecular Reaction Statics (AMRS),the correct electronic states and the reasonable dissociation limits for the ground states of diatomics UO,UC,UN and UH are derived.By using the MP2(the HF calculation followed by a second order Moller Plesset correlation) method of Gaussian94W program and the RECP potential(the relativistic effective core potential) for U and basis 6 311G  or 6 31G  basis set for light atoms(O,C,N,H),the equilibrium geometry,dissociation energy,spectroscopic data and the analytical potential energy functions of UO,UC,UN and UH are derived for the first time,the thermodynamic formation functions at 0.1 kPa and 298 K(Δ H f 0, Δ S f 0,Δ G f 0) are in fairly good agreement with the experimentally obtained data.