--for 2005
select * from sys.index_columns where object_id = object_id('MyTable')
--for 2000 and 2005
select * from sysindexkeys where id = object_id('MyTable')
select * from sys.index_columns where object_id = object_id('MyTable')
--for 2000 and 2005
select * from sysindexkeys where id = object_id('MyTable')
参考MSDN: