At present Genetics is one of the sciences, which develops with extra - high speed and has become an exact science as physics and mathematics. Meanwhile, in Vietnam as in many other countries this subject is taught in classical way following historical sequence of concepts and don’t distinguish reason - consequence relationship of concepts. This situation creates mismatches between the current tremendous content of genetics in the curriculum and teaching methodology. That’s why we have decided to rewrite textbooks on the subject.
The subject was rearranged, basing on two principles:
• Replace the historical sequence which we have used up-to-now, with logical sequence;
• Place causing concepts before consequence concepts.
Thanks to the application of a new approach, the teaching volume as well as textbook content has been reduced substantially. The activity of pupils has changed very positively as they have to study consequence concepts (about 80%) by themselves relying on the causing concepts (20% left) without teacher ’ s lessons. Furthermore, it is not necessary to re-educate teachers because the subject content was only rearranged, not modified nor added. This new methodology has been applied to a simplified textbook for a project of European Union (EU) and recently fully applied to three books published in Vietnamese. The new approach has been presented at six national workshops across Vietnam and a trail teaching was done in three secondary schools in Hanoi.