Latar belakang: Kepadatan penduduk menjadi penyebab utama pencemaran air Sungai Jangkok, Kota Mataram. Hal ini dikarenakan sumber pencemaran sangat dominan berasal dari limbah rumah tangga berupa limbah cair dan sampah yang dibuang langsung ke sungai. Oleh karena itu, perbaikan aspek sosial adalah bagian yang sangat penting dalam program pengendalian pencemaran air di Sungai Jangkok. Penelitian ini bertujuan untuk menganalisis pengaruh perilaku dan kondisi permukiman masyarakat terhadap kualitas air di Sungai Jangkok, Kota Mataram.Metode: Pengumpulan data dilakukan dengan wawancara semi-struktur menggunakan kuesioner sedangkan data kualitas air sungai menggunakan data sekunder dari Dinas Lingkungan Hidup Kota Mataram. Analisis kualitas air sungai menggunakan metode STORET. Untuk mengatahui pengaruh perilaku dan kondisi permukiman masyarakat terhadap kualitas air sungai menggunakan analisis regresi logistik dengan software SPSS.Hasil: Status mutu air pada bagian Hulu, Tengah dan Hilir Sungai Jangkok, Kota Mataram menurut sistem nilai STORET dikategerikan buruk (tercemar berat). Pencemaran tersebut utamanya ditandai oleh tingginya nilai BOD, COD, minyak dan lemak, besi terlarut, E. coli serta Total Coliform. Berdasarkan analisis kuisioner diperoleh gambaran bahwa perilaku dan kondisi permukiman masyarakat secara umum dikategorikan kurang baik. Terutama pada perilaku membuang sampah di sungai, perilaku pencegahan, sarana pembuangan air limbah dan layanan pengelolaan sampah. Berdasarkan analisis regresi logistik variabel Perilaku dan Kondisi Permukiman Masyarakat memiliki nilai signifikansi kurang dari 0,05 dan odds ratio lebih dari 1.Simpulan: Perilaku dan kondisi permukiman masyarakat berpengaruh siginifikan dan positif terhadap kualitas air Sungai Jangkok. ABSTRACT Title: The Impact of Community Behavior and Settlement Conditions on Water Quality in the Jangkok River, Mataram CityBackground: The high population density is the main cause of water pollution in the Jangkok River, Mataram City. This is due to the fact that the major source of pollution comes from household waste in the form of liquid and solid waste, which is directly dumped into the river. Therefore, improving the social aspect is a crucial component of the water pollution control program in the Jangkok River. This study aims to analyze the influence of community behavior and settlement conditions on water quality in the Jangkok River, Mataram City.Method: The data collection was conducted through semi-structured interviews using questionnaires, while the water quality data of the river were obtained from the secondary data of the Mataram City Environmental Agency. The analysis of the river water quality was carried out using the STORET method. To determine the influence of community behavior and settlement conditions on the water quality of the river, logistic regression analysis was performed using SPSS software.Result: The water quality status in the upper, middle, and lower parts of the Jangkok River, Mataram City, according to the STORET system values, is categorized as poor (heavily polluted). This pollution is primarily indicated by high values of BOD, COD, oil and grease, dissolved iron, E. coli, as well as Total Coliform. Based on the questionnaire analysis, it is found that the community behavior and settlement conditions are generally categorized as poor. Especially in terms of the behavior of disposing of waste in the river, preventive behavior, wastewater disposal facilities, and waste management services. Based on the logistic regression analysis, the variables of community behavior and settlement conditions have a significance value of less than 0.05 and an odds ratio of more than 1.Conclusion: The behavior and settlement conditions of the community have a significant and positive impact on the water quality of the Jangkok River.