Deforestation in the Wunbaik Reserved Mangrove Forest (WRMF) (22,919ha) has been accelerating since the 1990s. This study focuses on the causes of deforestation and the changes in the livelihoods of the local people. Forty percent of the mangrove forest in the WRMF was lost from 1990 to 2011, when a shrimp pond and a paddy field, known as a ‘kari,’ were created and logging operations were initiated. According to interviews with the members of 104 households of kari farmers, 50% of these farmers had earned their livelihood by fishing before they started to farm, but had changed over tokari farming in the WRMF because of a higher cash income. Deforestation in the WRMF is the result of low enforcement of the Forest Law, and thus strong land-use policies at the national and local levels are necessary to prevent further deforestation in this area.