I solved it. the text is utf-8
const string Str = "×گض¸×¨ض´×™×،ض°×کוض¹×ں";
Encoding defaultEncoding = Encoding.Default;
byte[] bytes = defaultEncoding.GetBytes(Str);
Encoding encoding2 = Encoding.UTF8;
string hebrewString2 = encoding2.GetString(bytes);
label1.Text = hebrewString2;
Thanks for every body