Abstract: In this book chapter, we argue that the distinction between "structure" and "style" is important in understanding the similarities and dissimilarities in common and civil law property. Structure is the functional form the law employs to protect people’s use interests, whereas style is a manner of delineating entitlements that is characteristic of a particular legal culture. The same structure of property can be implemented in a number of styles. For transaction costs reasons, property systems under the two traditions (common and civil laws) are similar and have to be similar. Their styles today, as is well known, are quite different, due to their different histories and path dependence. To underpin our point that it is critical to look beyond property styles to understand the economic nature of property, we closely examine mortgage (called hypothec in civil law countries). The styles of mortgage/hypothec cannot be more different. Several countries consider mortgage a property right; several others delineate it as a contract; while some others view it as neither property nor contract. We demonstrate that mortgage/hypothec, like other, uncontroversial property interests, contains the three essential elements of property. Thus, in terms of structure, mortgage/hypothec is a property right in all jurisdictions, despite the wide variety of styles in the civil and common law systems.