Utilizing all-components waste concrete without separation treatment as alternative raw materials to produce recycled cement is a significant method to recycle waste concrete in original resource level.Hardened cement paste (HCP) from waste concrete is the characteristic component of recycled cement raw materials.Hydration products and unhydrated cement particles (UCP) from HCP will carry out a series of physical and chemical changes in calcination process, which impacts the clinker calcination process and clinker mineral properties.This paper mainly studies the effect of UCP on calcination process of recycled cement clinker.The HCP with different hydration degrees were prepared by using Portland cement P.Ⅱ52.5 to replace 0~30% of full-hydration hardened cement paste (99.3% hydration degree).Artificial waste concrete, prepared by mixing HCP, limestone and silica fume (substitute of sand) in the mixing proportion of four-components concrete (C40), was used to prepare recycled cement raw meal with UCP in different proportions.Burnability test of raw meal and petrogTaphic analysis of clinker were the main test methods.On this basis, the study on effect of the added CaF2 dosage on bumability and microstructure of clinker with high-content (30%) UCP in its raw meal was also carried out.The results indicates: recycled cement raw meal with the proportion of UCP over 5% presented poor burnability;when UCP excessed 15%, the content of C2S in clinker presented an increasing tendency, and the clusters of Blite that affected the early strength of recycled cement paste appeared in different degrees;CaF2 contributed to the improvement of burnability of recycled cement raw meal with UCP in high content, and the optimum dosage is 0.5%.