Sibling relationships contribute to the healthy mental development of each individual. Its importance has been increasingly accentuated both in clinic practices and academic research during clinical practices and academic research over the past few years. This review intends to investigate siblings' influence on individual development through the lens of psychoanalysis and the vicissitude of sibling relationships in psychoanalytical theories and practice. Sibling relationships and sibling objects have as lasting an influence on the patients as their parents. Discerning these factors will be a boon not only to the positive progress of the therapy but also to the perfection of related theories. This review will contain the following three parts: 1) the shift from overly-emphasized parent-children relationships to the emerging sibling factors; 2) sibling relationships presented in psychoanalytical cases; 3) the influence of sibling relationships on psychoanalytical therapy and individual growth.