Classroom is the most important place in the educational institutions. It is the focal point of all learning activities. This study was designed to investigate the interaction between teachers and students, and students to students within the classroom. This study started with the review of the literature; many studies were found which have analyzed different aspects of classroom life. A need was fell to see the relationship between teachers'' verbal interaction and students'' academic achievement. The population of this study consisted of all secondary level science teachers of government high schools in Bahawalpur. A sample of 45 science teachers was purposively selected and their intact classes (405 students) were also taken as a part of the sample. The major objectives of the study were to explore the time spent on each component of verbal interaction in teaching of science through the analysis of classroom interaction at secondary level, and to find out the relationship between teacher interaction and academic achievement of students. Seven research questions about lime spent in each component of interaction, relationship between interaction and academic achievement, and the effect of different types of interactions on the levels of learning of students, were formulated to address these objectives. A sixteen category observation schedule was used to analyze teacher student interaction in the classroom. In a typical setting of the classroom there were a number of ways of interaction but the most significant among them was the teacher student interaction. Although, theoretically, teachers have a large number of teaching methodologies on their disposal but in real settings it was revealed that most of the teachers, in the sample used, typical lecture method mixed with inductive or deductive reasoning. As patterns of teaching are concerned, it was found that most of the classroom lime was xvdevoted to talk, Most of the talk time was consumed by the teacher. Most of the talk time was spent in direct talk i.e. lecturing, questioning-answering, giving directions. Demonstrations, students’ questions, acceptance of students’ feelings and using the ideas of students were given less time in teacher student interaction. It was concluded that the academic achievement of the students is directly influenced by teachers’ talk time devoted for one component or the other in their respective classrooms. The interaction between students and teachers was analyzed to find out different aspects according to the classroom dynamics. lire correlation between teacher interaction''s aspects and the academic achievement of students'' was calculated. The results of the correlations showed that lectures of the teachers enhanced students’ knowledge level’s academic achievement while question answers were more correlated to higher level’s learning. Student-student talk other than question-answer had been negatively correlated with students’ academic achievements. In the end it was concluded that it is not necessary to divide classroom time 50:50 among teacher and students but proper utilization of time is more important. Some recommendations are given in end especially for the teachers that they may be able to focus on students’ higher level learning through a better interaction in their classrooms.