The main cause is on Thursday morning I insert about 10 million of data to a table. Using the sysfiles I can view that the log file has grown then on Thursday night a full backup occurs and I expect the log file to truncate. If this does not happen then the next day I manually execute the DBCC SHRINKFILE(Logfilename) to truncate the log file.I want to avoid this and SQL Server should some how truncate the log file. Some times the table insert occurs on Monday or friday so the log file even grows on that day.I want the log file to truncate the next day.