Effects of different modifiers such as waste of soda manufactory, spent mushroom compost, sludge and turf on improvement of acid soil, and its effect on growth, yield and quality of pepper were researched by soil pot culture experiments. The results showed that all modifier treatments could increase pH value of the acid soil, the contents of organic carbon, available (nitrogen, phosphor, kalium)and exchangeable(Ca and Mg) in the soil. Therefore, the modifier treatments alleviated the Al toxicity to the pepper seedlings,and improved the yield and the quality of pepper to different degrees. A significant correlation was found between the content of exchangeable Al and fresh weight of pepper roots. Among all of the treatments, compost of the waste of soda manufactory with spent mushroom had the most prominent effects on alleviation of Al toxicity and improvement of growth and yield of pepper. With the soil treated with the compost, the SPAD value, the plant height, the fresh weight of roots and shoots and the yield of pepper increased by 17%, 32%, 244%, 45%, and 189%, respectively. The content of vitamin C and water-soluble sugar in pepper treated with the compost was 1.78 and 2.77 times as high as that of control. It could be concluded that the waste of soda manufactory and the spent mushroom compost have demonstrated a good complementarity in regulating the soil acidity and improving fertilizer in soil.