The study is aimed to change traditional practices of rice cultivation (using conventional, unbalanced fertilizers and too many seeds) of farmers in acid sulfate soils with 2 rice crops/year in Hoa An commune, Phung Hiệp district, Hậu Giang province. Cultivation model under the improved farming method (improved model) using NPK slowly released fertilizer, urea humate, potassium humate and reduced seeding amount were conducted through two rice crops (Winter-Spring 2018 - 2019 and Summer-Autumn 2019) with an area of 3000 m2 / model. The results showed that the improved model had a higher pHH2O, the amount of available phosphorus in the soil increased, the Al3+ and H+ content decreased, significantly different from the control model. The productivity of the improved model rice was (6.19 tons/ha) significantly higher than that of the control model (5.67 tons/ha) in the Winter-Spring crop. In the following crop (Summer-Autumn crop) there was no statistically significant difference in rice yield between the improved model (5.57 tons/ha) and the control model (5.05 tons/ha). The improved model helped farmers save 30% of the seed sowing seed, 50% of the amount of N and P fertilizers, and gain higher profits (by 5.4 and 3.5 million VND/ha, respectively for Winter-Spring and Summer-Autumn crops).