I have not worked on Web Services, but now I am planning to work on WCF Services in my next web application project. Do we need to have prior working experience on Web Services to work on WCF ?
can we start learning/working on WCF directly with out working experience in Web Services ?
You do not need any prior experience in web services to use WCF, though it would of course help in some situations. Having said that, WCF does have a learning curve (like everything), so you should consider going through some training, like the excellent Pluralsight training.
In addition to some sort of training, a must have resource for WCF in my opinion is Juval Lowy’s book, Programming WCF Services.
Good luck!