how to know the database logs of DELETE operation

SQL Server provides fn_dblog function to know the details of DELETE log records....
fn_dblog helps you to view the transaction log records in the active part of the transaction log file for the current database.

For knowing active log records of DELETE operation, use Operation as 'LOP_DELETE_ROWS'

SELECT DISTINCT [Transaction ID],  Operation,  Context,  AllocUnitName    
FROM  fn_dblog (NULL, NULL)  
WHERE  Operation = 'LOP_DELETE_ROWS '