The purposes of this study were to i) Examine the dynamics of physicochemical parameters of saline acid sulfate soil as influenced by biochar made from rice husk; and ii) Evaluate the influence of biochar on the soil quality index. A greenhouse experiment was carried out by mixing biochar with the tested soil at ratios of 0; 0.7; 1.5; 3, and 6% (w/w) and incubating for 100 days. Experimental soil samples were taken on days 5, 15, 30, 60, and 100 to analyze for 11 physicochemical parameters. The soil quality index (SQI) was calculated based on the principal component/factor analysis (PCA/FA). The results showed that biochar increased the exchangeable concentration of K, Mg, Ca, and pH value while reducing the exchangeable concentration of Fe, and Al, as well as the values of Cl-, H+, and exchange acidity in the soil. Biochar changed the electrical conductivity (EC) and Na parameters, increasing them in the first few measurements while decreasing them in the last measurements. Biochar increased the SQI of the tested soil, even with a low biochar application rate of 0.7% after 100 days of the experiment. The study suggests that biochar made from rice husk could be a potential amendment for ameliorating saline acid sulfate soil.