Same property rental revenue generally refers to revenue generated by properties within a Real Estate Investment Trust (REIT) Same Property Portfolio, which usually consists of properties acquired before the beginning of the accounting period.
This is in contrast to the Total Property Portfolio and properties that were acquired after the start of the accounting period.
For example, if Boston Properties (BXP) owns a building prior to 2008, rent from that building is included in 2008 same property rental revenue. In contrast, if it buys a property after the start of 2008, it is not included.