DT0-activated carbons modified with HCl and HNO3 acids, which were used for the first time in the catalytic process of alpha-pinene isomerization, are presented in this study. The carbon materials DT0, DT0_HCl, DT0_HNO3, and DT0_HCl_HNO3 were examined with the following methods: XRF, SEM, EDX, XPS, FT-IR, XRD, and N2 adsorption at -196 °C. It was shown that DT0_HCl_HNO3-activated carbon was the most active material in the alpha-pinene isomerization process. Detailed studies of alpha-pinene isomerization were carried out over this carbon by changing the reaction parameters such as time (5–180 min) and temperature (60–175 °C). The 100% conversion of alpha-pinene was achieved at the temperature of 160 °C and catalyst content of 5 wt% after 3 h over the DT0_HCl_HNO3 catalyst. Camphene and limonene were the main products of the alpha-pinene isomerization reaction.