http://gqshen.com/archive/193
1. Run SQL query
show variables like ‘%character%’;
to check the character sets of the database. If the character_set_database is latin1, change it to utf8 by
alter database mydb character set utf8;
where mydb is the name of the database.
2. Edit wp-config.php, change the line
define(‘DB_CHARSET’, ‘utf8’);
to
define(‘DB_CHARSET’, ”);