How to: Set the History Retention Period (SQL Server Management Studio)
Specify the history retention period on the General page of the Distribution Database Properties - <DistributionDatabase> dialog box. This setting controls how long replication agent history is stored. This page is available from the General page of the Distributor Properties - <Distributor> dialog box. For more information about accessing this dialog box, see How to: View and Modify Distributor Properties (SQL Server Management Studio).
To specify the history retention period
On the General page of the Distributor Properties - <Distributor> dialog box, click the properties button (…) for the distribution database.
Enter a value in the Store replication performance history at least box.
Click OK.