Abstract: Dali picrite in Yunnan Province occurs at the bottom of Emeishan basalt in the inner zone of Emeishan Large Igneous Province (ELIP). The picrite is highly porphyritic with 20%~40% euhedral-subhedral olivine and clinopyroxenite phenocrysts, and the groundmass with diabasic texture is composed of microcrystalline olivine, clinopyroxenite and plagioclase with minor spinel. SiO2 content of most picrites ranges from 45.94% to 46.37%, lower than 47%, except for one sample, whose SiO2 content is up to 47.35%. In all picrite samples, MgO is higher than 18%, varying between 19.01% and 23.77%, and total Na2O+K2O is lower than 2%, ranging narrowly from 1.52% to 1.97%, which indicates the features of typical picrites. Whole-rock Re content shows a narrow range from 0.349×10-9 to 0.424×10-9, while Os has a wide range from 0.889×10-9 to 4.276×10-9; in addition, the whole-rock 187Re/188Os and 187Os/188Os ratios vary from 0.437±0.012 to 2.708±0.025 and from 0.1283±0.0002 to 0.1354±0.0004, respectively. The estimated 187Os/188Os ratios of the matrix range from 0.1380 to 0.1415 by the Mass Balance Calculation. By contrast, all Re (0.030×10-9~0.049×10-9) and Os (0.625×10-9~0.757×10-9) values of the olivines separated from the picrites are lower than those of whole-rock data, and the 187Os/188Os ratio of the olivines ranges from 0.1254±0.0005 to 0.1268±0.0005, lower than that of the whole-rock. The spinel separated from the picrites has the highest Os content up to 80.6×10-9 and the lowest 187Os/188Os ratio down to 0.1252±0.0003. Compared with features of the Primitive Upper Mantle (PUM), the matrix Re-Os isotopes have the crust lava affinity, while the olivine and spinel show residual mantle features. γOs values of the separated minerals (olivine and spinel) are between -2.01 and -2.59, indicating that the rock-forming materials might have originated from the depleted sources instead of from such rich or fertile areas as the boundary of the core-mantle, while the γOs values of whole-rock vary from -1.11 to -3.24, obviously the mixing result of olivine, spinel and matrix. It is inferred that the formation of ELIP should be attributed to the interaction between the crust and the mantle.