Tujuan penelitian ini adalah untuk mengetahui dan menganalisis pengaruh variabel keputusan pembelian (iklan dan brand ambassador) secara parsial, terhadap keputusan pembelian pada marketplace tokopedia. populasi dalam penelitian ini adalah mahasiswa yang berada di kota tarakan yang pernah menggunakan aplikasi tokopedia dan mengetahui iklan dan brand ambassador bts. sampel dalam penelitian ini berjumlah 120 responden. dengan teknik purposive sampling. metode pengumpulan data menggunakan kuesioner. pengujian hipotesis yang digunakan dalam penelitian ini adalah analisis regresi linier berganda. berdasarkan hasil uji hipotesis yang dilakukan diketahui dua variabel yaitu, iklan (x1) dan brand ambassador (x2) dimana kedua variabel tersebut mempengaruhi keputusan pembelian (y), dapat dilihat bahwa variabel iklan t hitung (5,529) > t tabel (1,657) dan signifikan 0,001 < 0,05 dan variabel brand ambassador t hitung (3,459) > t tabel (1,657) dan signifikan 0,001 < 0,05. dengan demikian dapat disimpulkan bahwa variabel iklan dan brand ambassador berpengaruh signifikan terhadap keputusan pembelian pada marketplace tokopedia. kata kunci: iklan, brand ambassador, keputusan pembelian.

The purpose of this study was to determine and analyze the effect of purchasing decision variables (advertising and brand ambassadors) partially on purchasing decisions on the tokopedia marketplace. the population in this study were students in the city of tarakan who had used the tokopedia application and knew bts advertisements and brand ambassadors. the sample in this study amounted to 120 respondents, which were taken using purposive sampling technique. a questionnaire was used to gather the data. the data were analyzed using multiple linear regression analysis. it was determined from the results of the hypothesis testing that there were two variables, namely advertising (xi) and brand ambassadors (x2), where these two variables affected purchasing decisions (y) both the advertisement variable (t count, 5.529) and the brand ambassador variable (t count, 3.459), which were significant at 0.001 and 0.05 respectively, were observed. in light of this, it was shown that factors such as advertising and brand ambassadors significantly and favorably affected consumer decisions on the tokopedia marketplace. keywords: advertising, brand ambassador, purchase decision.