This study aims to analyze and prove the influence of brand image, reference group, and Lifestyle partially and simultaneously on iPhone smartphone purchase decisions for generation Z in Surabaya. The study used a quantitative approach. The sampling technique in this study was performed using Nonprobability sampling and Purposive sampling is a sampling technique based on the characteristics of at least 17 years old., domiciled in East Surabaya and has used or is using an iPhone Smartphone with a sample of 100 respondents. Data tests used are instrument test, classical assumption test, t test and F test. Data analysis using linear regression multiple coefficiency determination (R2). The results of the research show that the brand image variable has a significant influence on the decision to purchase a generation Z iPhone smartphone in Surabaya, the reference group has a significant influence on the decision to purchase a generation Z iPhone smartphone in Surabaya, lifestyle has a significant influence on the decision to purchase a generation Z iPhone smartphone in Surabaya, and brand image, reference group, and lifestyle simultaneously have a significant influence on purchasing decisions for Generation Z iPhone smartphones in Surabaya.