Synaptidae was one of holothuroidea member, unique because they has no podia or tube feet in their surface of body wall and has no respiratory trees in their internal organ. They has anchor shape spicules in their body wall that supporting locomotory function. Synaptidae were frequently found in the sea grass area, but no publication was specifically observed their existence. This study proposed to observed the species of synaptidae in Sanur Beach-Bali, included their length distribution and their vegetation preference to live with. The observation was conducted twice time using swept survey time based method (one hour) on low tide. The results shows 46 individual of synaptidae consist of two species (Synapta maculata and Opheodesoma grisea) found in the intertidal zone of Sanur Beach-Bali. In the first observation, most of synaptidae had shorter body length then in the second observation. Almost all of synaptidae observed was associated with Enhalus acoroides. Synaptidae in the study area adapt to a very extrem environment. Their adaptation were: 1) osmoregulation to the fluctuation of salinity; 2) wide tolerance of temperature fluctuation; defense mechanism to the wave motion by 3) having sticky skin and 4) autotomy mechanism.