Forests malaria is one of the epidemiological prototypes related to ecological conditions. Major changes in the forest environment cause changes in the pattern of malaria transmission and the transmission of primate malarias to humans has made forest malaria more highlighted recently. During 2013, a cases finding of malaria and passive case detection have been conducted. Case finding of malaria was done by survey to residents around the forest and the people who work in the forestry sector. Passive case detection conducted in some health facilities in Central Kalimantan and South Kalimantan, in order to determine the extent of the transmission of primate malaria, Plasmodium knowlesi, to humans. The results presented in this paper is about the parasite rate of microscopic examination results in all locations and risk factors of malaria transmission. Results shown that the Slide Positivity Rate (SPR) at the village level ranged from 0% to 12%, and most infections occured at male and age of > 15 years. In Central Kalimantan, the results indicated no significant difference of SPR between the miners and non-miner (P <0,0001) with an OR of 7,25 (95% CI: 3,08 to 17,08). In South Kalimantan, there is a significant difference of SPR between loggers and non-loggers (P <0,0001) with an OR of 5,4 (95% CI: 3,1 to 9,5). In conclusion, forest is one of the suitable environment for malaria transmission in Central Kalimantan and South Kalimantan with the highest transmission is among adults and males. In Central Kalimantan, forest miner is five times more at risk of malaria than non-miners. Whereas in South Kalimantan, logger is seven times more at risk of malaria than non-logger. It is recommended that the local government should intensify malaria case finding surveillance in both occupation.