in this paper, the notion of injectivity with respect to order dense embeddings in the category of $s$-posets, posets with a monotone action of a pomonoid $s$ on them, is studied. we give a criterion, like the baer condition for injectivity of modules, or skornjakov criterion for injectivity of $s$-sets, for the order dense injectivity. also, we consider such injectivit...