High birth rate should encourage the growth of baby care products and make them an attractive market segment. However, there is a significant decline in brand index regarding big brands. This indicates the intense competition in this segment. Hence, marketers must compete more effectively. One of them is by optimizing social media marketing activity. The purpose of this study is to learn the influence of social media marketing activity that is mediated by customer equity, in relation to purchase intention on baby care products. Respondents in this study amounted to 164 people who are consumers of baby care products that are active in social media, such as Instagram. In this study, the researcher used likert scale. Sample collection was done by non-probability sampling method and convenience sampling technique. For data analysis the researcher used structural equation model (SEM) with SmartPLS3. In this study, it was found that there is significant influence between social media marketing activity and value equity, relationship equity, brand equity and purchase intention, whereas the biggest direct effect of purchase intention was found on brand equity, with value 0.426. Furthermore, it is proven that value equity and brand equity are able to mediate the influence of social media marketing activity towards purchase intention. While relationship equity has no effect in mediating the relationship between social media marketing activity and purchase intention. The R-square value of purchase intention was found to be 0.582. Contents regarding babies health updates and interesting visuals were found to be the key factor on the decision to follow the social media accounts of baby care products. This research can provide managerial benefits through its findings. Further research is needed on different categories of baby care products. / Angka kelahiran bayi yang tinggi seharusnya dapat mendorong pertumbuhan produk baby care dan menjadikannya segmen pasar yang menarik. Namun terjadi penurunan brand index pada brand besar. Hal ini mengindikasikan persaingan yang ketat pada segmen ini. Pemasar harus berkompetisi lebih efektif salah satunya dengan mengoptimalkan social media marketing activity. Tujuan dari penelitian ini adalah untuk mempelajari pengaruh social media marketing activity yang dimediasi customer equity terhadap purchase intention pada produk baby care. Responden dalam penelitian ini berjumlah 164 orang yang merupakan konsumen produk baby care yang aktif di media sosial seperti Instagram. Dalam penelitian ini digunakan skala likert. Pengumpulan sampel dilakukan dengan metode non-probability sampling dan teknik convenience sampling. Untuk analisa data digunakan structural equation model (SEM) dengan SmartPLS3. Dalam penelitian ini ditemukan pengaruh signifikan yang positif pada social media marketing activity, value equity, brand equity dan purchase intention, dimana pengaruh langsung terkuat terhadap purchase intention ditemukan dari brand equity sebesar 0,426. Lebih lanjut value equity dan brand equity terbukti mampu memediasi pengaruh social media marketing activity terhadap purchase intention. Sedangkan relationship equity tidak berpengaruh dalam memediasi hubungan antara social media marketing activity terhadap purchase intention. Nilai R-square dari purchase intention ditemukan sebesar 0.582. Content tentang kesehatan bayi yang update dan menarik visualnya ditemukan menjadi faktor yang paling menarik perhatian dalam keputusan memfollow akun media sosial produk baby care. Penelitian ini dapat memberikan manfaat manejerial melalui temuan-temuan seperti diatas. Penelitian lebih lanjut diperlukan pada kategori yang berbeda dari produk baby care.