C:\>SQLPLUS "/ AS SYSDBA"

SQL*Plus: Release 9.2.0.1.0 - Production on Mon Oct 6 11:15:52 2008

Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.


Connected to:
Oracle9i Enterprise Edition Release 9.2.0.1.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.1.0 - Production

SQL> CREATE USER TTT IDENTIFIED BY "TT@TT";

User created.

SQL> GRANT CONNECT,PUBLIC TO TTT;

Grant succeeded.

SQL> CONNECT TTT/"TT@TT"@ORCL
Connected.

------解决方案--------------------
使用密码的时候用引号""引用起来就可以了

------解决方案--------------------
只需要把密码的那部分括起来，即可。
在密码或用户名的连接串里带有自己的"@"字符，实在是有些讨苦头吃。