Hi Tung Thanh,
Is your technology information set up correctly? For example, does the tech file have a prRules section, a prViaTypes section ?
Which version are you using of the tools (e.g. what does "abstract -W" return, are you using icfb (CDB-based) or virtuoso (OA-based) for the design framework?)
Have you looked at the Abstract tutorial? `cds_root abstract`/tools/dfII/samples/tutorials/abstract
I hope that this information helps you to generate a LEF file.