Thank you for the answer.

I run the sample database named demo.db:
C:\Users\Public\Documents\SQL Anywhere 12\Samples\demo.db

I executed the Upgrade Database Wizard. Despite the wizard told me that the jconnect support is already installed in my database, I finished the upgrade. It still not works. Then, I executed the query you have mentionned in the tool named "Interactive SQL". And sadly, I'm still not able to get a ParameterMetaData.

Here is the java code I run:
DriverManager.registerDriver((Driver)Class.forName("com.sybase.jdbc3.jdbc.SybDriver").newInstance());
con = DriverManager.getConnection("jdbc:sybase:Tds:10.23.75.23:2638", "DBA", "sql");
PreparedStatement pstmt = con.prepareStatement("SELECT ID, GivenName, Surname FROM Customers");
ParameterMetaData paramMetaData = pstmt.getParameterMetaData();
if (paramMetaData == null)
{
System.out.println("ERROR: db vendor does NOT support ParameterMetaData");
}
else
{
System.out.println("SUCCEED: ParameterMetaData is supported");
}

You may try on the same sample database with this command:
java -cp .;jconn3.jar JDBCConnect jconnect > output.log