Updated project metadata. Interkingdom Pseudomonas-Candida biofilms is a human pathogen associated with acute and chronic infection. This study examine hoe their structural organization influences their in vivo microenvironment, which in turns affects the interaction of Pseudomonas-Candida biofilms with host immune responses. NCI-H292 grown P. aeruginosa biofilms with and without C. albicans biofilms were used for proteomic analysis. Biofilms were demonstrated in all groups which have 357 proteins from proteomic analysis including i) proteins in PA+CA were higher than PA (76 proteins, such as sigma factor AlgU negative regulatory protein; MucA) and ii) proteins in PA+CA were lower than PA (281 proteins, including alginate genes such as Alginate biosynthesis transcriptional regulatory protein; AlgB). Although most of Pseudomonas proteins in PA+CA were lower than PA due to the lower initial bacteria in preparation of mixed-organism biofilms, mucA overexpressed in PA+CA indicating that high alginate production that transcriptionally controlled by algU-mucABCD genes. These results demonstrated that Pseudomonas-Candida biofilms produced alginate more compared to Pseudomonas biofilms on lungs.