Most of the coastal community depend heavily on the natural resources found in the coastal area, but at the same time, the way they used the resources also deteriorate those resources. In some area in Maluku Province, sasi as indigenous knowledge has been used for hundreds of years as a tool in the management of natural resources like fish, molluscs, crustacean, etc. This study was conducted at Rutong and Leahari village of South-Leitimur Sub-district, Ambon city to find out the implementation of sasi in the management of mangrove ecosystem. The result shows that there is a positive relationship between community attitude towards the implementation of sasi in the management of mangrove ecosystem with strong correlation (r = 0.815). More than 60% of the community support the implementation of sasi in the management of the mangrove ecosystem to maintain the sustainability of that ecosystem.