i just contact info@elastic.co to request , and then i recived a license in my email. and the license has one year valid.
curl -XGET localhost:9200/_license?pretty
{
"license" : {
"status" : "active",
"uid" : "cbcf567e-44c6-4e20-94fd-0e3fb040d91a",
"type" : "basic",
"issue_date" : "2016-04-27T00:00:00.000Z",
"issue_date_in_millis" : 1461715200000,
"expiry_date" : "2017-06-13T23:59:59.999Z",
"expiry_date_in_millis" : 1497398399999,
"max_nodes" : 100,
"issued_to" : "jiang peng (china citic bank credit card center)",
"issuer" : "Web Form"
}
}