Abstract: By High Frequency Reciprocating Rig test (HFRR), the relationship of the changes in lubricating properties of diesel products with sulfur content，polycyclic aromatics content before and after storage were studied. Resins were separated from diesels by solid phase extraction (SPE), and then studied on their lubricating property. The acidity and the varieties of basic nitrogen compounds in diesels were analyzed before and after storage. The results show that the lubricating properties of diesels with low solidification point is easy to become worse after storage. However, large changes in lubricating properties after storage will appear for the diesels with low content of sulfur and polycyclic aromatic. One reason that leads to the better lubricating property is the increase of acidity and the basic nitrogen compounds with lower hydrogen deficient number (z value) after storage. The lubricating properties of diesels will become worse after resins were separated out.