Land use changes are so prevalent in almost all regions in Indonesia, including in Purwakarta Regency. Purwakarta Regency is located between Jakarta City as the capital city of Indonesia and Bandung City as the provincial capital of West Java. The conversion of agricultural were due to the pressures from other land uses. Agricultural land use changes certainly have implications for microclimate changes. The objectives of this study were to analyse changes in paddy fields due to the pressure from other land use conversion and to formulate solutions for land conversion control policy. The study was conducted in Purwakarta Regency, including the Citarum watershed area. The studied area has a total of 62,398 ha out of the total 97,172 ha of the whole Purwakarta. The study used the Spatial Dynamics Analysis approach with Powersim Studio and IDRISI to predict the land changes in the year 2030. The simulation showed that paddy field areas decreased to 36.07 % from 20,394 ha in 2012 to 13,036.90 ha in 2030. On the contary, residential areas increased as much as 105.94 % from 5,418.44 ha in 2012 to 11,158.7 ha in 2030. The loss of paddy fields totalling to 8,668.21 ha from 2009 to 2030, has implications on the microclimate changes with the economic value of environmental services, in particular prevention of an increase temperature, of IDR 2,812,240,804,033.00. Policies are needed to clearly define the spatial land use with regional regulations to control paddy fields conversion, implement Sustainable Food Crop Areas owned by the government with farmer empowerment and develop derivative products by utilising the wastes.