I just to ask, my xray says that i have a past tb, but i never have any treatment it is possible that it will heal itself?

Tb: Dending on your PPD reading and other findings, you may need to have a course of treatment to clear a latent infection. An infectious disease specialist can determine the best course of action.

Yes: Echidna: what they are likely seeing on your chest xray are calcium deposits called granulomas. These are very common and seen with many forms of granulomatous disease of which TB is one. So it doesn't mean it's definitely old tb, but some old, healed granulomatous process of some sort. You will always have them and they are nothing to worry about.