[quote user="李杨 Li Yang"]When I try to access property via oPH.SelectByAccessString("property"), I get result false[/quote]
In addition to Jan's suggestions, what happens if you test your functionality using MicroStation VBA?
Your C# code calls VBA through an InterOp. If your code does not work in VBA, neither will it work in C#. We all have VBA, so when you post a code example we can reproduce it.