The field experiment was conducted to study microbial product and urea effects in decomposing rice straw on the growth and yield of rice grown in acid sulfate soils in a three rice cropping system, at Tam Nong district, Dong Thap province, in the Autumn-Winter crop of 2016. The experiment was carried out in factorial design with 2 factors in randomized complete blocks with 3 replications. The first factor - treatment of Urea- included: (1) untreated (2) treated with Urea. The second factor - type of microbial products- included (1) untreated, (2) treated with Trichomix-DT, (3) treated with TricôĐHCT-Lua von (4) treated with Dascela. The results showed that incorporporation of rice straw treated with Dascela increased the number of full grains per panicle (78 fully grains per panicle), the number of panicles per m2 (447,7 panicle /m2) and grain yield (5,95 t/ha). The combination of rice straw treated with Dascela and Urea increased density of Cellulomonas flavigena bacteria and the number of tillers per m2. Urea treatment increased density of Cellulomonas flavigena bacteria.