Land forest convertion that has been become estate area be to change microclimate. Two climate factors is very effect to index comfort, that are temperature and relatif humidity. Genarally, the temperature and relative humidity in tropical area is high and it can increase body heat load because heat environment. Therefore, the research about effect land forest change function into area estate to variation of comfort index. The temperature and relative humidity interaction that contribute to comfort index to calculate based on Temperature Humidity Index. On oil pslm site research and the open site was recorded temperature and relative humidity are 26ºC and 72,0% and 28.0ºC and 76,0 %, respectively. Interaction temperature and relative humidity created discomfort index (THI) was different on those research site. On mixed cropping, oil palm site, rubber and pen site, THI value is 73.0, 79.9, 82.0, and 85.1 that mean many of people was felt discomfort surrounding oil palm and the open site. The mixed cropping as secondary forest that was changed rubber and oil palm estate to contribute increase discomfort index about 9% and 12%, respectivey, for a while if rubber estate was changed into oil palm estate be contribute about 3%. A trend up discomfort index was possible if a location be open. The closed conservation area in estate will be contribute to minimize discomfort index Keywords: microclimate, discomfort index, mixed cropping, oil palm, rubber