<form name="loginform" id="loginform" action="<?php bloginfo('url') ?>/wp-login.php" method="post">
    <label>Логин<br />
        <input type="text" name="log" id="user_login" /></label>
    <label>Пароль<br />
        <input type="password" name="pwd" id="user_pass" /></label>
    <label><input name="rememberme" type="checkbox" id="rememberme" value="forever" /> Запомнить меня</label>
    <input type="submit" name="wp-submit" id="wp-submit" value="Войти" />
    <input type="hidden" name="redirect_to" value="<?php bloginfo('url') ?>/wp-admin/" />
    <input type="hidden" name="testcookie" value="1" />
</form>