Because the characteristics of geochemistry in sedimentary rocks contain lots of geological information, it has a great significance for restoring the sedimentary environment and discussing the provenance. The upper Yunlong Formation in Yunnan Lanping Basin consists of a set of carbonate rocks and its overlying clastic rocks. Through the study of major, trace elements and REE for carbonates and clastic rocks respectively, the results and geochemical characteristics can be concluded as followed： the total ∑REE of carbonate and clastic rocks range from 14265×10-6~18685×10-6 and 2172×10-6~4837×10-6, 16744×10-6 and 3587×10-6 in average respectively. The (La/Yb)N values range from 8.22~10.96 and 9.07~15.01 respectively, the standard curve inclined right which indicate the light rare earth elements enriched compared with heavy rare earth elements. Negative Eu anomalies were in a medium level, negative Ce anomalies of three mudstones were very strong, and other samples show no significant negative Ce anomalies. According to the eigenvalue Ce/Ce* which is the most sensitive about redox environment, the upper Yunlong Formation sedimentary period was mainly in an oxidizing milieu, the sedimentary period of carbonate rocks was in a weak oxidizing milieu and some stages was in relatively reducing milieu, and the mudstone was in the most oxidizing milieu, the siltstone took second place and carbonate rock took the last. Based on ∑REE and (La/Yb)n, Fe2O3/MnO, EF Mn, CaCO3(％) and Al(％), it can indicate that the stage of clastic rocks deposited was in a paleo climate of warm and wet environment, and the stage of carbonate rocks deposited was in a paleo climate of arid and hot environment, and had an alternate changes between drying and wetting at the same time. Sedimentary material source was from the upper continental crust, and consisted of mainly original felsic materials, and intermediate and intermediate mafic matetials.