I have get some information about ASP Web API. It is look like good stuff for web services but how to create something like WSDL for my API like WCF service does ? how 3d pa
As to whether it looks good, thats an opinion so try it and see (I personally like it)
As far as a WDSL the Web API is a RESTful API not SOAP based so there is no WSDL support, WCF has REST support and SOAP so that may be a better choice if you require a SOAP service and WSDL, ScottGu's latest blog on the API is quite interesting and has links to tutorials (the WSDL generation question is answered in the comments too)
http://weblogs.asp.net/scottgu/archive/2012/02/23/asp-net-web-api-part-1.aspx