The purpose of this work is to explore different types of intergenerational relationships in the later lives of old retirees. This will be done according to the eligibility of public pension and the old age social security system so that the factors affecting intergenerational relationships can be analyzed, and to propose a plan to improve social adaptation in later life. The data used in this work are the Fourth basic survey data of the 2011 Korea Retirement and Income Study. The study subjects of this work were 2,435 retirees over age 65 who had children. In this study, latent class analysis and logistic regression analysis were conducted to classify types of intergenerational relationships and to analyze the influence of relevant factors. As a result of the analysis, some of those in the group were eligible for public pension, and the ones who were not were classified into three types: the closely-living-together type, the separate-living-contact type, and the estrangement type. In the group not eligible for public pension, it was found that age, spouse, number of children, economic factors, and level of health satisfaction gave significant power to intergenerational relationships. In the group eligible for public pension, it was found that age, income and net assets, ADL(Activities of Daily Living), whether there was an IADL(Instrumental Activities of Daily Living) spouse, and number of children affected types of intergenerational relationships; Socio-demographic factors, economic factors, and healthy factors became significant variables according to the classified types of intergenerational relationship. Based on the study results, this work suggested such necessities to lay the foundation for an elderly welfare system for social adaptation in later life, This includes the offering of programs for retirement preparation, the use of family and local society resources, and expansion of the opportunity to participate in social activities.