This paper researches the inter-marital situation in Gangneung area during 16C from late Goryeo till early Joseon through the actual cases of Gangneung Choi family. The Gangneung Choi family has three branches of Choi Mun-Han(崔文漢). Choi Heun-Bong(崔欣奉) and Choi Pil Dal(崔必達). who had the inter-marital relation with indigenous families in Gangneung as high as 48~54%. 41 % and 44% of total inter-marriages respectively, In similar rates of around half, three families had the inter-marital relation with indigenous families in Cangneung. More concretely, they had it with other branches of Gangneung Choi family, Gangneung Kim family(江陵金氏), Gangneung Park family(江陵朴氏) and Gangneung Ham family(江陵咸氏) in order. That is, three Choi branches had the dose inter-marital relation with each other and Gangneung Kim family and Gangneung Park family in Gangneung region. It must be because they shared the political, social and economical interests in the region. When the inter-marital ratio was checked in Gangneung jurisdiction or vicinity region. Choi Mun-Han had 57~64% of the total inter-marital relations with indigenous families in Gangneung vicinity region. while Choi Heun-Bong and Choi Pil-Dal had 51 % respectively. Especially, they had many inter-marriages with Samcheok Kim family(三陟金氏) and Samcheok Sim family(三陟沈氏). In the generational change, they showed the fluctuation of 37%~58%, 31%~50% and 31~52% respectively. With about 10% fluctuations from the averages, all the three branches had 3~5 of 10 inter-marriages with indigenous families in Gangneung area. They showed little increasing or decreasing in the marital tendency over generations. It must be because Gangneung has an isolated topographic condition with Taebaek(太白) Mt. Ridge and suffered few social changes due to it. And it turned out that Gangneung Choi family had little bond with other typical Cangwon areas(江原道) like Wonju(原州) and Chuncheon(春川) through the inter-marriage. In the actual marriage situation. Gangneung Choi family had duplicative and repetitive inter-marital relation with other indigenous families in Cangneung generation over generation. When a girl of the Choi family got married to a boy of other family, their kids married again with Gangneung Choi family members. In these inter-marriages, there were sorre cases of consanguineous marriage and ignorance or reversal of generation and kindred degree. Therefore, even if Gangneung Choi family had 51~60% of total inter-marriage with indigenous families in Gangneung area, actual ratio seemed much higher because the inter-marital relation was linked again with Gangneung Choi family through other family names. This type of inter-marriage must have an important role for Gangneung Choi family to maintain the social previledge in Gangneung.