Which folder I use for recovery mysql database
Accidently deleted mysql database ...

It happens.
It shouldn't be the End of the World.

... and reload again.  But I cant find my old database ...

Not sure what you mean by &quot;reload&quot; but if you did anything that involved running &quot;create database&quot; for that particular database then anything and everything about the old database has now been obliterated.

... and no have backup.

This is hard lesson for any DBA to learn and, sadly, you've learned it the Hard Way:

Any Data that you don't have at least two copies of is Data that you do not care about and are perfectly content to lose.

You must take Backups of your databases, for the very reason that, sometimes, when things go badly wrong, you have to Recover them.
If you have backups of the machine itself, you might be able to get something back by restoring the data files from that but do not expect to get everything back.  Databases do a lot in memory, so any files copied out from &quot;under&quot; a running database instance are not consistent.