Someone told me that Kibana 4.x is not free to use on production, to use it on product, we need pay for license, Is that true?
It is released under the Apache 2.0 open source licence and is free to use in production.
This is the second time in a couple of days that this question pops up, and when looking at https://www.elastic.co/subscriptions it's easy to understand why. Perhaps that page can be updated to make it more clear that you don't need a subscription to use any components in the stack in production?
So, per that page, the subscription is only needed for support from ES?
But I think at least marvel & shield are commercial products, they are not free to use on product, am I right?
Correct. Marvel, Watcher, and Shield are commercial products that are included in some of the paid support plans according to https://www.elastic.co/subscriptions. Those paid support plans are not needed for Elasticsearch, Logstash, Kibana, or any of Elastic's other open source products.