This study investigates phonological variations of the Gyeongsang dialect speakers in dialect contact situations in Seoul. This study also examines what factors have significant effects on these phonological variations. It focuses on social factors: ‘gender’, ‘language attitude’, ‘length of residency in Seoul’ and in particular, ‘age group’ that is classified based on whether the participants received compulsory education where standard Korean is used. The tendency of the phonological variation is disproportionate for each phonological variable. In direct dialect contact situations in Seoul, Gyeongsang dialect speakers undergo phonological variation almost all the phoneme and phonological rule but the relatively low toneme. But this quantitative loffwness of the variation degree on toneme variant is not absent in the knowledge of the phonological pattern of Seoul Korean, but rather is hard to adapt or habituate it. In other words, the achievement of toneme variation requires a certain amount of acquisition period compared to the other variants. This study shows that it may take about 20 years to adapt to the phonological patterns of Seoul Korean. The statistical analysis of phonetic data suggests that all social factors investigated in this study influence a speaker's frequency of use of the Seoul Korean variants. Especially, each age group shows different tendency of influence of social factors. Old speaker group influences by social factors in the following order: ‘gender’, ‘length of residency’ and ‘language attitude’. In the case of young, on the other hand, the order is ‘language attitude’, ‘length of residency’ and ‘gender’.