The study aimed at checking the existing level ofunderstanding of concepts in the subject of Chemistryamong Class IX students and to investigate theeffects of concept formation teaching model overtraditional method. 460 students were selected from Government High Schools for Boys and Girls ofRawalpindi city for administering a test to measurethe existing level of understanding of concepts inthe subject of Chemistry among Class IX students. Forexperiment, sample size was 290. Pre-test-Post-testNonequivalent-Groups Design was used. Pre-test andpost-test were administered to both groups at thebeginning and end of the experiment. 31 lesson planswere made on the format of direct instruction fromChemistry textbook for Class IX. The data wasanalyzed by applying t Test, Product-MomentCorrelation and ANCOVA. It reveals that existinglevel of understanding of concepts was not up to 50percent. The experimental groups outscoredsignificantly the controlled groups on post-testshowing the supremacy of concept formation teachingmodel on traditional method. Concept formationteaching model appeared to be favorable for both boysand girls for the understanding of concepts.