手足關係除了是個人生命中相當重要的家庭關係外，也是許多人一生中最為長久的關係。然而在家庭相關的研究中，多半圍繞在夫妻與代間關係上，對手足關係的研究相對有限，也鮮少針對改變關係或是互動的因素進行探討。為此，本文使用「華人家庭動態調查」的三波資料，來探討重大生活事件在各個時期中如何影響臺灣成人在中老年時的手足關係。從研究結果我們可以發現：(1)在生命事件中，不同的婚姻狀態會影響個人與手足間的互動頻率。而在個人處於已婚或是同居的狀態下，他們與手足的互動會隨著波次有所增加；在工作狀態方面，成年受訪者在有兼職工作時與沒有工作的人相比，他們與手足聯絡、互動的頻率較高；最後則是父母健在狀態，父母的過世會讓手足們因為失去共同經歷而降低彼此的互動頻率。(2)從年齡效果來看，個人隨著年齡的增長，他們反倒會減少與兄弟姐妹的接觸、互動。(3)此外在手足互動頻率的個體差異上，受訪者若為女性、手足結構為同性別組成的臺灣成年，則會擁有較低的互動頻率，而健康狀況較好、手足規模大或肯定傳統家庭價值觀的人，則有較高的互動情況。(4)最後，本研究試圖從性別的視角分析在手足關係中，臺灣成年的生命事件異質性。與成年男性相比，成年女性在結婚、父母雙亡或成為母親後會減少與兄弟姐妹的互動、聯絡，說明手足互動頻率會隨著生命事件的經歷和性別而有所差異。透過這些發現，也進一步捕捉個人手足關係在生命歷程中的動態變化。

The relationships with siblings are the longest ones for many people in their lifetime. However, research on sibling relationships is limited in comparison with studies of intergenerational solidarity or dynamics within couples. There are even fewer studies that have investigated the variation in sibling interactions or factors contributing to the changes in sibling connections over the life course. To fill the gap in the literature, building on the life course perspective and using data from the Panel Study of Family Dynamics (PSFD), this research examines the ways in which major life events affect the relationships of middle-aged and older Taiwanese adults with their siblings over time. The findings show that some life events, such as marriage and parenthood, yield substantial effects on the frequency of contact with siblings. Specifically, for the sibling relationships of same respondents over time, individuals report higher rates of contact with their siblings when they are married than when they remain single. With regard to employment, Taiwanese people interact with their siblings less frequently when they have full-time jobs than when they are not in the labor force. In addition, as individuals age, they reduce their contacts with their brothers or sisters. In terms of the differences in frequencies of contact with siblings among individuals, females and people with only brothers tend to interact with their siblings less frequently while marrieds, and people in better health, having more siblings, or strongly adhering to traditional family values, report higher rates of contact with their brothers and sisters. Interestingly, compared with their male counterparts, women decrease their contacts with siblings if they enter into marriage, experience the death of both parents, or become mothers. These findings shed additional light on the dynamics of sibling relationships over the life course.