After the Sassanids defeated the Parthians and came into power, they considered attributed themselves to the Achaemenian dynasty, and they considered the Parthians as foreigners. Therefore, Sassanids tried to underestimate the effects of the Parthian rule. However, in the past centuries, with the increase of archeological studies, it was found that the Parthians had a great share in transmitting culture and art to the Sassanids. The purpose of this study is to investigate how the Parthian art affects the Sassanid art by studying the art of the Parthian and Sassanid eras and citing architectural works, rock reliefs and coins. The research question indicates that in what fields and to what extent the motifs of Sassanid art have been influenced by Parthian art. The research method is descriptive-comparative, and the data are obtained from documentary studies. The results show that despite the efforts of Sassanid rulers to downplay the Parthian government, much of Parthian art has had an undeniable impact on later art, so this effect is clearly evident in the art of architecture, the visual structure of coins, and Sassanid rock reliefs. In addition, this effect was more in the early Sassanid period and in the field of architecture. Patterns such as the goddess of Nike and animals such as horses and boars, and plant motifs such as artichokes and lotus flowers, common in Sassanid rock reliefs, are indebted to Parthian art. Also, by quoting coins, religious themes of the fire altar, moon, and star, giving diadem and general image of Sassanid coins, are influenced by Parthian coins.