Knowledge and behavior possessed by students is the main key to the concept of preparedness in flood disasters in Samarinda City. This study aims to determine the level of knowledge and behavior of SMA Negeri 4 Samarinda students towards flood disaster preparedness. This study uses a quantitative descriptive method. Sampling in this study used the Quota Sampling technique with a sample size of 30% of the population, namely 213 students. Data collection techniques in this study were in the form of questionnaires, observations and interviews. Data analysis techniques in the form of research instrument trials, analysis prerequisite tests, multiple linear analysis, knowledge and behavior analysis. The results showed that the knowledge of floods possessed by Samarinda 4 Public High School students was included in the high criteria with an average score of 54% which included learning knowledge, age, environmental factors, and information. The results of students' behavior in dealing with floods are included in the very high criteria with an average score of 49% which includes the levels of accepting, responding, appreciating, and being responsible. The results of the analysis of the coefficient of determination (R2) as a measure of the influence of knowledge (X1) and behavior (X2) on the dependent variable, namely on the preparedness variable (Y) shows that the value of R2 is 0.689. It can be concluded that knowledge and behavior have an influence of 68.9% on preparedness variable.Pengetahuan dan perilaku yang dimiliki peserta didik merupakan kunci utama dari konsep kesiapsiagaan dalam bencana banjir di Kota Samarinda. Penelitian ini bertujuan untuk mengetahui tingkat pengetahuan dan perilaku peserta didik SMA Negeri 4 Samarinda terhadap kesiapsiagaan bencana banjir. Penelitian ini menggunakan metode deskriptif kuantitatif. Pengambilan sampel pada penelitian ini menggunakan teknik Quota Sampling dengan jumlah sampel sebesar 30% dari populasi yaitu 213 peserta didik. Teknik pengumpulan data dalam penelitian ini berupa kuesioner, observasi dan wawancara. Teknik analisis data berupa uji coba instrumen penelitian, uji prasyarat analisis, analisis linear berganda, analisis pengetahuan dan perilaku. Hasil penelitian menunjukkan bahwa pengetahuan tentang banjir yang dimiliki peserta didik SMA Negeri 4 Samarinda termasuk ke dalam kriteria tinggi dengan nilai rata-rata 54% yang mencakup ilmu pembelajaran, umur, factor lingkungan, dan informasi. Hasil perilaku peserta didik dalam menghadapi bencana banjir termasuk kedalam kriteria sangat tinggi dengan nilai rata-rata 49% yang meliputi tingkatan menerima, merespon, menghargai, dan bertanggung jawab. Hasil analisis koefisien determinasi (R2) sebagai pengukur besarnya pengaruh pengetahuan (X1) dan perilaku (X2) terhadap variabel terikat, yaitu terhadap variabel kesiapsiagaan (Y) menunjukkan bahwa nilai R2 sebesar 0,689 maka dapat disimpulkan bahwa pengetahuan dan perilaku mempunyai pengaruh sebesar 68.9% terhadap variabel kesiapsiagaan.