The Murray Darling Basin (MDB, -27- -38^oS, 138-152^oE) and the North China Plain (NCP, 31-40^oN, 112-122^oE) are important agricultural production areas in Australia and China respectively. Although MDB and NCP are located in the southern and northern hemisphere respectively, they lie at similar latitudes (with slightly different longitudes), and both have temperate climate with similar annual rainfall range in most parts. The farming systems also have many similarities. However, they have different climate patterns and seasonality, which lead to distinct production and environmental problems. While the similarities facilitate easier research and technology transfer, the uniqueness of production and environmental problems in MDB and NCP offer new opportunities for enhanced collaborative research to improve systems sustainability. Both MDB and NCP are facing severe sustainability problems as a result of changed water balance by the agricultural production systems. In the southern MDB replacement of deep rooted perennial native vegetation with shallow rooted annual crops/pastures have significantly reduced plant water use and root zone soil water storage, which in turn has increased drainage beyond the plant root zone and ground water recharge, leading to rising groundwater table and dryland/river salinity. In contrast, in northern NCP, where intensified double cropping systems rely heavily on irrigation from groundwater. Irrigation, together with increased industrial and domestic water use, has led to over use of fresh groundwater, causing a severe decrease in groundwater resources. Management of water balance of farming systems in MDB need to target on high water use systems, whereas in NCP agricultural systems that have lower water use need to be introduced to mitigate or reverse the decline in the ground water resource.This paper presents a comparative study on water balance of farming systems at two selected sites: Wagga Wagga (-35.05^oS, 147.35^oE) in MDB and Luancheng (39^oN, 113^oE) in NCP. A farming systems model and long-term historical climate data were used to simulate crop production and water balance of the current dominant cropping systems. Production and resource degradation problems that are in common and unique to both sites were analysed. Possible new crop types with improved physiological traits, alternative cropping systems and management options were explored to study their impact on economic return and water balance. A detailed discussion was focused on the essential biophysical processes and properties of current farming systems, which need to be modified in order to improve the environmental outcomes, while to maintain a certain level of productivity of agricultural systems at both sites. Due to the flat nature of the landscape in regions around both study sites, the potential impact of water balance change through cropping systems and management modifications on areal groundwater recharge can be assessed. Such assessments are combined with available regional water resource data (groundwater and surface water) to study what are sustainable levels of water use by crop production systems in both regions and their implications on water balance. To meet such water balance targets, the changes that need to be made to the current cropping systems (mainly wheat–maize/wheat-cotton double cropping in NCP and crop-pasture rotation system in MDB) are discussed. Current agricultural production targets set by different research/government agencies are reviewed.