Hi,
I am planning to install two nodes clustered sql server, should I install
domain contraoller in both nodes with one is PDC and another is BDC?or it
has to be PDC only?

MS recommends that you only install a SQL Server cluster on domain controllers if no other DCs are available within the domain. This may be the case where SQL Server is being introduced into a non-Windows environment. Generally it is not good practice to put SQL on DCs. If you need to, make sure you create both nodes as DCs BEFORE installing clustering. For full details see:

http://support.microsoft.com/default...kb;EN-US;28166