Giant freshwater prawn (Macrobrachium rosenbergii de Man, 1879 is one of important aquaculture species in the Mekong Delta and Vietnam. Farming of giant freshwater prawn so far very well-known in the freshwater area with some important systems especially the alternative rice-prawn farming system on the seasonally flooded rice field ini Dong Thap, An Giang and Can Tho province. However, this industry has recently expended rapidly and largely to the brackish water area, especially in Ben Tre, Tra Vinh, Bac Lieu , Ca Mau and recently Kien Giang provinces. A survey showed that, there is currently 15,270 ha of  prawn culture in the Mekong Delta with total production of 5,306 tons, of which coastal provinces cover for 90.1% of total culture area and 64.8% of total production. Two important systems for prawn culture are (i) Prawn cum rice farming on field alternatively with tiger shrimp culture; and (ii) Prawn culture in ponds alternatively with tiger shrimp culture.  For the system (i),  the fields are 2.2 ha in area; prawn culture density was 1.1 inds/m²; prawn were mostly not fed or casually fed with byproducts; and average yields 110 kg/ha/crop and net income of 11.5 millions VND/ha/crop were achieved. For the system (ii),  the ponds were in average of 0.6 ha; stocking density was at 8.9 inds/m²; prawns were fed properly with pellet feed or combined with homemade fed and trashfish; and yield and net income of 886 kg/ha/crop and 68 million VND/ha/crop were obtained. Prawn culture share low production cost rates but contribute large ratio and improve significantly the total income of the farming systems. The analysis indicated that prawn culture in water salinities of 5 - 10‰ have growth performance, yields and income similarly or significantly better than those in the lower salinities. The success of the farming systems together with a large area of brackish water surface in the Mekong Delta gives the industry a great potential for further development. This helps diversify culture species and farming systems for sustainable aquaculture in the region, especially supports as of important solutions to adapt to climate change. Further studies and investment for the farming systems are needed.