4Qiang Xiang HUANG,Ji Xiang MENG The College of Mathematics and Sciences. Xinjiang University. Urumqi 830046. P. R. China Fu Ji ZHANG The Department of Mathematics. Xiamen University. Xiamen 301005. P. R. China.Infinite Circulant Digraphs and Random Infinite Circulant Digraphs[J].Acta Mathematica Sinica,English Series,2002,18(4):817-822.