Traditionally Kim Yoosin is valued as a greatstatesman and a great commander who ultimately achieved unification of Three Kingdoms. But he was and valued as a typical figure ruind autonomy of Korean autonomy from nationalistic point of view since the Japanese compulsory occupation of Korea. And in taking critical stance on the idea of the unification of Three Kingdoms, some are underrate his achievements and discribes him as a figure immersed in partisan interests.However he and his family did nothing but endeavor to survive in aristocracy of Silla constantly. Therethrough, they contributed to the unification of Three Kingdoms and beginning of the royal family mid Silla by military power. In that process, occasionally, they drived sordid stratagems. But those were inevasible choice and outgrowth of their own volition.In 7thcentury, he and his father and granfather were, Three Kingdoms struggled fiercely. Specially, Silla was on the defensive in this times. The capture og Daeyasung-Castle brought about direct crisis in family of Kim yoosin and royal family of King Jinji. Kim yoosin pursued conquest of Baekje to resove crisis ultimately. The result is so-called the unification of Three Kingdoms.The family of Kim yoosin had no choice but to capitulate cause of weak military force. But The family of Kim yoosin grew military power, finally joined in aristocracy of Silla. So he and his family military power could contribute to Silla`s needs of military power as a way to overcome crisis. Thus Kim yoosin and his family could take part in the unification of Three Kingdoms as a historical route with military power which is their own means of survival. We can find historical meanings of Kim yoosin and his family`s achievement.