title in page.html.twig I find out title is not exists in page.html.twig, and there is a file page-title.html.twig to theme title, then in block section we should use block title. ( ** I don't want use this strange structure for title,really I  didn't find out why Drupal do this  !!!).

any way 
I want to provide it by myself, maybe hook_preprocess_page is solution,any body know how can I add title variable to page variables ?
This is my solution for adding title to page templates.
in yourthemename.theme add 

function hook_preprocess_page(&amp;$vars) {
    if(isset($vars['node'])) {
        $vars['title'] = $vars['node']-&gt;title-&gt;value;
    }
    else{
       $vars['title'] =$vars['page']['#title'];
    }
 } 


then title exist in page templates.