The middle hall mural at Longju Temple is an example of classic Ming Dynasty temple murals in Sichuan. In order to ascertain the material and workmanship of the mural, the structural morphologies and material compositions of samples were analyzed using microscopy, laser particle analysis, X-ray diffraction (XRD),Raman spectrometry,and enzyme-linked immunosorbent assay (ELISA), etc. The results show that the structure the mural depends on is a mud wall with a bamboo skeleton. The mineral components of the plaster layer are mainly quartz and albite. The grain composition of the mural is powder in the majority and sand in the minority. In the Diangongban mural the coarse mud layer has a lower sand content and a higher powder content than the fine mud layer. The fibers in the coarse plaster layer are straw stalks and chaff and those in the fine plaster layer are cotton or fibrilia. Regarding colors, the red pigments are cinnabar and minium, the green pigments are atacamite and paratacamite, the white pigments are calcite and talcum, the black pigment is carbon black, the blue pigment is azurite, and the yellow pigment is goethite. The cementing material is animal glue or egg white. The mural is typical, in terms of carrier structure, plaster materials and color composition, compared with other murals of the same region and period. These research results could not only provide guidance for the following protection and restoration of the mural in the future, but also enrich the knowledge of ancient architectural murals in this area.