Value of type '1-dimensional array of cannot be converted to 'System.Collections.Generic.List()

 Hi, guys
I use web service as the data layer, and there is a web service function returns  list(of Contact)  (contact is a class defined by myself)
and in my presentation layer, If I tried to do 
dim result as list(of contact) = ConWebService.getContactList()

there is always an error message says Value of type '1-dimensional array of cannot be converted to 'System.Collections.Generic.List(),
,and I assumed that after the webservice, the result will become type Array instead of List,
if I try do
Dim dd As New Ar ...