Doctor told me i have kidney infection but i do.not have any symptom . no vomiting no pain no fever.. is it possible ? to have it without symptoms?thx

Yes: It is possible to have mild bladder infection without many symptoms. But here the context is missing such as why was the test to check for kidney infection done. What were the symptoms for which this test was done etc.

Unlikely: It is unlikely to get UTIs and kidney infections without symptoms however your dr would have based the diagnosis on your urine tests which is the most definite way of diagnosing a kidney infection