A polishing slurry composition is provided. The polishing slurry composition includes abrasive particles, an oxidizer, an iron-containing catalyst, and a stabilizer, and a retention rate of the oxidizer according to Equation 1 is 70% or greater. Retention rate (%) of oxidizer=(concentration (%) of oxidizer after 7 days at room temperature×100)/(initial concentration (%) of oxidizer in polishing slurry composition)  [Equation 1]