Untuk berkomunikasi dengan siswa secara efektif dan kemampuan antar pribadi yang mumpuni adalah sangat penting bagi guru. Berdasarkan pengamatan, interaksi guru-siswa memainkan peran utama dalam prestasi akademik siswa. Fenomena ini teramati dengan jelas dalam pembelajaran biologi sekolah PJL College. Tetapi, ada terdapat 50% siswa yang tidak lulus nilai ulangan tengah semester. Karena itu, peneliti memutuskan untuk menyelidiki ada tidaknya hubungan antara sikap antar pribadi guru-siswa dan prestasi belajar biologi kepada 63 siswa kelas X di sekolah PJL College. Metode penelitian ini adalah kuantitatif korelasional. Analisis data dilakukan dengan menggunakan statistik deskriptif dan teknik korelasi r pearson. Metode pengumpulan data yang digunakan adalah beragam yaitu, nilai rapor tengah semester, survei dan observasi. Adaptasi terhadap kuesioner interaksi guru di kembangkan untuk mengukur sikap antar pribadi guru dan interaksi dengan siswa dalam kelas. Penelitian ini dimulai pada 3 Agustus hingga 13 November 2015. Hasil penelitian menunjukkan bahwa nilai rata-rata prestasi belajar siswa melewati kriteria ketuntasan minimal yaitu, 73.16. Selain itu, sikap antar pribadi guru berhubungan signifikan dengan prestasi belajar siswa. Secara khusus, terdapat enam dimensi yang berkorelasi signifikan seperti sikap kepemimpinan, ramah, memahami, bimbang, menegur, dan tegas. Tetapi, ada dua dimensi yang tidak berkorelasi signifikan seperti kebebasan siswa dan ketidakpuasan guru. / To communicate effectively with the students and to have strong interpersonal skills are very much important for teachers. Based on the observation, teacher-student interaction plays a major role in influencing students academic performance. This phenomenon was observed clearly in learning biology at PJL College. However, there were more than 50% of students who did not passed on Midterm test. Therefore, the researcher decided to investigate whether or not the associations between teacher-student interpersonal behavior and learning achievement towards biology among 63 tenth grade students at PJL College. Correlational method was used as a methodology in this research. Data analyses were conducted by using descriptive statistics and r pearson correlational techniques. Various methods were used to collect the data, which were mid-term report card, questionnaire and an observation. An adapted version of the Questionnaire on Teacher Interaction (QTI) is developed to assess the interpersonal behaviors of the teachers and the interaction with the students in the classroom. It began from August 3rd until November 13rd 2015. The results show that the mean-value of students achievement had passed minimum completeness criteria that set by the school. Besides, teachers interpersonal behavior were significantly related to students’ learning achievement. In particular, there were six dimensions that significantly correlated such as leadership, helpful, understanding, uncertain, admonishing, and strict. However, there were two dimensions that did not correlate such as student freedom and dissatisfied.