The present invention aims to maximize the advantageous physical properties of sulfur and provide a cathode mixture that can be suitably used in a cathode mixture layer of an all-solid-state lithium sulfur battery exhibiting excellent charge/discharge capacity. The present invention also aims to provide an all-solid-state lithium sulfur battery including a cathode mixture layer containing the cathode mixture. The present invention provides a cathode mixture for use in a cathode mixture layer of an all-solid-state lithium sulfur battery, the cathode mixture containing: (A) an ion-conductive material containing phosphorus at a weight ratio of 0.2 to 0.55; (B) sulfur and/or its discharge product (B); and (C) a conductive material, the amount of the component (B) being 40% by weight or more of the total amount of the components (A), (B), and (C).