Aeromonas hydrophila is one of the bacteria that can cause disease in fish maintained in intensive systems. The main hazards that can be raised by these bacteria is that he can attack fish that are finger-sized man to cause mass death. Different ways to cope with this disease have been carried out, either through chemical treatment or by administration of antibiotics. The downside of this is the way that they can lead to resistance in fish, a cost is not cheap and can be toxic to fish. Some form of prevention that can be done to overcome this disease is to vaccinate the fish so the fish immune system can be improved. HOW TO GIVING Vaccination of fish can be provided through three ways, namely injection, soaking and mixing vaccines into fish feed. The most commonly used is the immersion because this way is seen as more simple and easy to do. Fish can be accommodated as many as 5,000 head of water in the tub with a capacity of 1m3 which kedealamnya mixed dose of vaccine is 25 cc. Immersion process carried out for 30 minutes before the fish is put back into the pool. MANUFACTURING ENGINEERING Hidrovet vaccine is made from pure cultures of Aeromonas hydrophila is kept in triptic soy agar (TSA). Cultures are maintained in the container room temperature (37 degrees C) for 1 full day. These bacteria can be harvested by applying the system to dry them and then dissolved in sterile phosphate buffer salime. Bacteria that have been harvested can be disabled by means of 0.5% phenol and can be dismpan. These bacteria are still viable for use although it has been stored in less than 3 months.