In this modern era, especially in this pandemic situation where social distancing is highly demanded in hope for minimizing the spread of Covid-19, e-commerce become one of the popular platforms for people to do their business online. Bukalapak is one of big e-commerce platforms from Indonesia, that founded by Achmad Zaky, Muhammad Fajrin Rasyid, and Nugroho Herucahyono in 2010. Bukalapak purpose is to provides a platform for SMEs in Indonesia. As in this pandemic era many offline businesses also do their business online. Which attract writer interest in finding customers social experience when purchasing in Bukalapak, especially in Medan. So that Bukalapak can improve their platform, services, promotion and their relationship with customers in Medan. The purpose in this study was to analyse the effect of Perceived Herd Behavior (PHB), Subjective Norm (SN), Peer Communication (PC), Emotional Support (ES), Parasocial Interaction (PI) on Customer Intention to Purchase (IP) in Bukalapak, Medan during Pandemic Covid-19 Situation. This study is causal research. The method used is quantitative methods of processing the data using the Structural Equation Model (SEM) with AMOS. Data was collected by distributing questionnaires to 120 respondents with the characteristics of male and female respondents, aged 18-60 years that have already use Bukalapak platform to purchase products or services they offer. The result of this research shows that Perceived Herd Behaviour has a positive and significant effect on Customer Intention to Purchase with regression coefficient value of 0.478; Subjective Norm has a positive but not significant effect on Customer Intention to Purchase with regression coefficient value of 0.412; Peer Communication has a positive but not significant effect on Customer Intention to Purchase with regression coefficient value of 0.419; Emotional Support has a positive but not significant effect on Customer Intention to Purchase with regression coefficient value of 0.411; Parasocial Interaction has a positive and significant effect on Customer Intention to Purchase with regression coefficient value of 0.64./Di era modern ini, terutama dalam situasi pandemi dimana social distancing sangat dituntut dengan harapan dapat meminimalisir penyebaran Covid-19, e-commerce menjadi salah satu platform yang diminati masyarakat untuk melakukan bisnis secara online. Bukalapak merupakan salah satu platform e-commerce besar asal Indonesia yang didirikan oleh Achmad Zaky, Muhammad fajrin Rasyid, dan Nugroho Herucahyono pada tahun 2010. Bukalapak bertujuan untuk menyediakan platform bagi UKM di Indonesia. Seperti di era pandemi ini banyak pebisnis offline juga melakukan bisnisnya secara online. Yang menarik minat penulis untuk mencari pengalaman sosial pelanggan saat melakukan pembelian di Bukalapak terutama di Medan. Sehingga Bukalapak dapat meningkatkan platform, layanan, promosi dan hubungannya dengan pelanggan di Medan. Tujuan dalam penelitian ini adalah untuk menganalisis pengaruh Perceived Herd Behavior (PHB), Subjective Norm (SN), Peer Communication (PC), Emotional Support (ES), Parasocial Interaction (PI) terhadap Customer Intention to Purchase (IP) di Bukalapak, Medan dalam Situasi Pandemi Covid-19. Penelitian ini merupakan penelitian kausal. Metode yang digunakan adalah metode kuantitatif yang pengolahan datanya menggunakan Structural Equation Model (SEM) dengan AMOS. Pengumpulan data dilakukan dengan menyebarkan kuesioner kepada 120 responden dengan karakteristik responden pria dan wanita, berusia 18-60 tahun yang telah menggunakan platform Bukalapak untuk membeli produk atau jasa yang mereka tawarkan. Hasil penelitian menunjukkan bahwa Perceived Herd Behavior berpengaruh positif dan signifikan terhadap Customer Intention to Purchase dengan nilai koefisien regresi sebesar 0,478; Subjective Norm berpengaruh positif tetapi tidak signifikan terhadap Customer Intention to Purchase dengan nilai koefisien regresi sebesar 0,412; Peer Communication berpengaruh positif tetapi tidak signifikan terhadap Customer Intention to Purchase dengan nilai koefisien regresi sebesar 0,419; Emotional support berpengaruh positif namun tidak signifikan terhadap Customer Intention to Purchase dengan nilai koefisien regresi sebesar 0,411; Parasocial Interaction berpengaruh positif dan signifikan terhadap Customer Intention to Purchase dengan nilai koefisien regresi sebesar 0,64.