using System; using System.Linq.Expressions; public class FooBase { } public class Foo : FooBase { } public interface IHelper { void DoIt (FooBase foo); } public class Program { public static int Main () { Expression> e = (helper => helper.DoIt (new Foo ())); var mce = e.Body as MethodCallExpression; var et = mce.Arguments[0].NodeType; Console.WriteLine (et); if (et != ExpressionType.New) return 1; return 0; } }