JEditorPane and/or HTMLEditorKit should be aware of HTML charactor encoding. Right now on 1.2 Beta4 "J", JEditorPane reads raw HTML file. It does not any character-set conversion when reading HTML. Try following program with Japanese HTML. I attached Japanese HTML file, encoded JIS.

$ java TestEditorPane index_ja.html Serif

-----
/*
 * %W% %E% koushi
 */

import com.sun.java.swing.*;
import java.awt.event.*;
import java.awt.*;
import java.net.*;

public class TestEditorPane extends JFrame {

    public static void main(String[] args) {
if(args.length != 2) {
System.out.println("Usage: java TestEditorPane <html_file> <font>");
System.exit(1);
}
        new TestEditorPane(args);
    }

    TestEditorPane(String[] args) {
        super("JEditorPane");
        addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
        try {
            URL url = new URL("file:" + args[0]);
            JEditorPane html = new JEditorPane(url);
            html.setEditable(false);
Font f = new Font(args[1], Font.PLAIN, 12);
html.setFont(f);
            JScrollPane scroll = new JScrollPane(html);
            getContentPane().add(scroll);
        } catch (Exception e) {
            System.out.println(e);
            System.exit(1);
        }
        setSize(500,300);
        //pack();
        show();
    }
}
-----

[koushi.takahashi@japan 1998-06-25]