Second phase particles (SPPs) of N18 zirconium alloys during seven manufacturing processes were investigated by means of quantitative metallography. The manufacturing processes include ingot-breaking, hot rolling, annealing, cold rolling, annealing, final rolling, and final annealing. The results of size, volume fraction, and distribution of SPPs were obtained after the software analysis. The key factors and control methods of SPPs growth in the rolling processing and the interaction between SPPs and grain boundaries in the later annealing process were also discussed.