Finally solved. Twitch api have an undoc feature '&_method=put' thru 'GET' =\
$.ajax({
url: 'https://api.twitch.tv/kraken/channels/mychannel?channel[status]='+titleStr+'&oauth_token=' +token+'&_method=put',
type: 'GET',
contentType: 'application/json',
dataType: 'jsonp',
success: function(data) {
console.log(data.status);
}
});
This code works well.