This manual provides a detailed description of the field inventory work that was implemented within the frameworkd "Monitoring, Reporting and Verification" (MRV) for Singapore's estimating and reporting of emissions and removals under the "Land use, land-use change and forestry" sector (LULUCF). The methods and procedures outlined in this manual cover all related field operations including the assessment of above-ground biomass, litter, and soils. The description is based on the field inventories carried out in 2015 and 2017, respectively. The manual serves as a guide for inventory managers and field crews in implementing the inventory word in a systematic and consistent manner, demonstratign the quality of the field operations, and assisting in maintaining the measuring standard for future re-assessments of the inventory plots.