This study aims to determine the effect of corn cobs and rice husk biochar on Vertisol chemical properties from Kupang Regency, East Nusa Tenggara. This study used a completely randomized design with two factors and three replications. The first factor is the type of biochar which consists of biochar of corn cobs and rice husks. The second factor is the dose of biochar (% soil weight), consisting of 4 levels: 1.5%, 3%, 4.5%, and 6%, and incubated for two months. Chemical properties observed in this study included pH, C-organic, and soil cation exchange capacity (CEC). The results showed that giving biochar of corn cobs and rice husks did not significantly affect changes in soil chemical properties.