Increasingly intensive aquaculture activities make the development of the disease increase. One of them is Vibriosis, a disease caused by pathogenic Vibrio bacteria. Several alternative disease prevention have been widely used. One of them is by using microalgae. This study aims to determine the effect of the use of microalgae in whole cells on the growth of pathogenic bacteria. Using 5 types of microalgae, namely Melosira sp, Phaeodactylum sp, Nannochloropsis sp, Porphyridium aerugineum, and Porphyridium sp with 105 cells/ mL of density. In vitro, the challenge test was carried out using a Complete Randomized Design with 6 treatments (5 types of microalgae and 1 control treatment without microalgae), which were repeated 3 times. While in vivo, it was carried out using PL 16 tiger shrimp with a density of 20 heads/jar volume of 20 L. The results showed that in vitro can give whole cell microalgae types P.aerugineum, Nannochloropsis sp, and Melosira sp can prevent the growth of luminous pathogenic Vibrio bacteria. While in vivo administration of microalgae Phaeodactylum sp and Porphyridium aerugineum may inhibit the growth of fluorescent pathogenic Vibrio bacteria better than other microalgae and control.