The impact of nucleation behavior and particle size distribution on the morphology of carbon black is investigated using a fixed sectional approach by applying the detailed chemical kinetic reaction for our previous experimental work. The development rate of the particle size distribution increases with an increase in temperature and the size of small particles (size below 10 nm) decreases with an increase in residence time. To form the complex aggregate shapes, three requirements should be fulfilled: (i) large particle number concentration, (ii) high nucleation rate, and (iii) quench before small particles of size belowlO nm collide with large particles consisting of a log-normal shape. The sensitivity of the furnace temperature on the particle size distribution and morphology of carbon black was further investigated by performing the calculation with the temperature being constant. With three requirements fulfilled, the aggregate shapes would become the most complex at 1850 K with a residence time of around 40 ms.