The purposes of the research were 1) to study the environmental developing activity administration 2) to study the model of environmental developing activity administration using the 3Rs principle 3) to propose the model of environmental developing activity administration with 3Rs of Thungtako network school under Chumphon primary educational service area office 2. The qualitative research was conducted in this study. Conditioning study data were collected by in-depth interviewing in 10 participants. Draft model data were collected from 3 participants using in-depth interview and focus group interview in 7 experts.

The results showed as follows: 1) the current conditions of environmental developing activity administration of Thungtako network school consist of morals, ethics, desirable characteristics by emphasizing students on doing integrated activities, learning and practicing to improve waste management behavior. 2) the model of environmental developing activity administration with 3Rs including (1) model title (2) rationale (3) objectives (4) procedure and (5) monitoring and evaluation which are in accordance with the 3Rs principle. The first principle of 3Rs is reduce, the second one is reused and the third one is recycle. 3) the model of environmental developing activity administration following the 3Rs principle of Thungtako network school showed that the environmental developing using the 3Rs principle supported the model that the researcher created under the experts supervision. This finding coud be applied for the highest benefits and great value for the school.