Background: Rosa damascena and Poria cocos are ingredients commonly used in Traditional Chinese Medicine. R. damascena is used to promote blood circulation as well as liver and stomach function, while P. cocos is used to eliminate dampness and enhance spleen function. Objective: The objective of the study is to investigate possible mechanisms by which R. damascena and P. cocos may promote immune function. Materials and Methods: Phagocytosis and dendritic cell (DC) surface marker expression assays were used to evaluate the effect of R. damascena and P. cocos extracts on human THP-1 monocytic leukemia cell biology. Results: R. damascena and P. cocos extracts both enhanced phagocytosis of latex beads by THP-1 cells, and when combined, phagocytosis was enhanced to a level greater than what might be expected by adding the individual phagocytosis responses together. In addition, both extracts enhanced maturation of THP-1 cells into a DC phenotype as measured by increased surface expression of the costimulatory molecules CD14, CD40, CD80, and CD86. Conclusion: These results suggest that Rosa damascena and P. cocos may promote monocyte phagocytosis and then stimulate differentiation of the cells into DCs thereby bridging innate and adaptive immune responses.