Display user field into html.tpl.php
U are setting $user variable inside if condition, while in if u have condition that $user->uid, so it will compute as false, and it will not go inside if condition.

You will have to write:

global $user;
if($user-&gt;uid) {
// Your code


// Edited

global $user;
$user_id = arg(1);

// $user_item = user_load($user-&gt;uid);

if($user-&gt;uid == $user_id) {
    echo 'I m connected';
    print render ($user_profile['field_mon_statut']);
}