Trace the Password Change History of Database Accounts

Oracle only tracks the date that the password will expire based on when it was latest changed. So by looking at the DBA_USERS.EXPIRY_DATE and subtracting PASSWORD_LIFE_TIME you can determine when password was last changed. The last password change time can also directly be seen from the PTIME column in dictionary table USER$ (on which DBA_USERS view is based).

If you have PASSWORD_REUSE_TIME and/or PASSWORD_REUSE_MAX set in a profile assigned to a user account then you can reference dictionary table USER_HISTORY$ for when the password was changed for this account. This will maintain any password which still falls with in the PASSWORD_REUSE_TIME and PASSWORD_REUSE_MAX limits.

Must Run this Query after connecting by Sys user

SELECT user$.NAME, user$.PASSWORD, user$.ptime, user_history$.password_date
FROM SYS.user_history$, SYS.user$
WHERE user_history$.user# = user$.user#