Abstract: A STUDY ON THE STABILITY OF GALLI UM COMPOUNDS Li Hongfeng; Liu Boli（ChemistryDepartment,BeijingNormalUniverty,100875） ABSTRACT The crystal data of more than14 0 gallium com pounds are used to calculate the sum of solid angle factors in the cone packing model． It is found that the solid angle factor sums（SAS）of all coordina-ting ligands reach to a stable region with an average value of 0．95 1 and a characteristic error σ=0．075． The stability of a few gallium compounds can be predicted by SAS ， and tested by ligand ex-change reaction. The experimental results are consistent with SAS. Key words cone packing model solid angle factor（SAF）stable region