A technique to control the mesoporous structure and crystallites present in turbostratic carbon (Ts-carbon) derived from Fe- and Ni-doped phenolic resin is described. To eliminate the effect of heat treatment temperature, all of the Fe- and Ni-doped phenolic resins are carbonized at a fixed temperature of 1000 °C. The catalyst content in the obtained Ts-carbon varies from 0.001 to 5 mmol/g. Mesopores and turbostratic crystallites are formed in the Ts-carbon samples, and these increase in size as the catalyst content and its particle size increases. The turbostratic crystallites assemble to form carbon aggregates with a cup-stacked, thin tube-like, or coil-like structure. The mesopore surface area increases proportionally with the amount of turbostratic crystallites rather than the type of carbon aggregate. It is proposed that the mesopore is surrounded by turbostratic crystallites. Altering the size of the turbostratic crystallites in Ts-carbon has revealed an effective method for controlling the size and volume of its mesopores.