The purpose of this study was to analyze the factors that influence middle-aged people's retirement planning and financial preparation for old age. The data was derived from "the National Survey of Families 2015". The samples included 1,462 people from 40 to 64 years of age. The findings from the analysis showed that the level of retirement planning was significantly associated with gender, age, education level, employment status, monthly family income, monthly expenditure on spending to support parents, and perceived household economic condition. When the samples were divided by sex, the results showed that the perceived household economic condition was the most significant factor for both men and women's level of retirement planning. Age and education level were the significant factors for women's level of retirement planning but not for men's. Logistic regression was used to analyze whether middle-aged people made financial preparation for old age. For the whole sample, whether or not a person was a regular employee, monthly family income, monthly expenditure on supporting parents, perceived household economic condition, and retirement planning were significant variables in determining financial preparation. For men, whether or not a person was a regular employee, monthly family income, perceived household economic condition, and retirement planning were significant factors, for women whether or not a person was a regular employee, and retirement planning were the significant factors in determining financial preparation. The results implied that retirement planning is needed for middle-aged people to prepare for old age financially while the financial preparation should differ depending on sex.