Hi Ramya,
For example my target web service endpoint is http://www.webservicex.com/globalweather.asmx
which is configured in my soap receiver channel so if you add ?wsdl to the above endpoint you will get wsdl url for the web service, using http://www.webservicex.com/globalweather.asmx?wsdl this url you can import the wsdl in soap UI.
When you import the wsdl the request will be target structure so you need to get the payload for this from message monitor in PI after the mapping and give in request tab of soap ui and test the web service you will get the response in soap ui.
Regards,
Praveen.