Abstract. Andayani S, Dadiono MS, Elwira WT, Setyawan FH. 2020. Potency of aloe extract as immunostimulant for carp (Cyprinus carpio) against Aeromonas salmonicida. Biodiversitas 21: 860-864. The objective of the study was to be able to know the cellular and humoral non-specific immune response to Aeromonas salmonicida after aloe extract administration. This study employed Complete Randomized Design with 3 treatments and 3 replications, control treatment (K), A =2 ppm of aloe extract application in the media, B = 16 ppm of aloe extract in the media, and C = 30 ppm of aloe extract in the media. The extract was given through one-hour soaking at day 0 and day 7, and then challenge-tested to 107 cells.ml-1 of A. salmonicida into the media for one day. Results showed that administration of aloe extract could raise plasma protein levels from 443.0 to 662.0 mg.Kg-1 antibody from 1.2576 to 3.3974, and phagocytic activity from 30.61% to 45.94%. Similarly, the differential value of leucocyte (lymphocyte from 58.6% to 73.70%, neutrophils from 6.09 to 8%, and monocyte from 5.70% to 7.72%). As conclusion, aloe extract at the dose of 2 ppm could raise the cellular and humoral non-specific immune. Therefore, the use of aloe extract as immunostimulant at the dose of 2 ppm applied through immersion could also apply other methods, such as oral and injection.