System approach and system dynamics were used as tools for the study and analysis of delivery care system in dental public health at district level to gain insights into system behaviors and factors Influencing changes of dental public health problems. Alternatives for problem solving were also developed and investigated together with the estimation of manpower requirement for dental public health at district level. Input data for the delivery care model in dental public health was collected from Praw District of Chaingmai Province in 1983 and 1988. The analysis of collected data and system behavious of dental public health system from 1983 to 2002 are shown as follows. 1. Deman for dental treatment will increase as population Increases. It increases from 76,920 hours in 1987 to 84,960 house in 2002 representing as average rate of increase of 0.52 per cent per annum. This low rate of increase is due to the deciline in average time service need per person during this period. It decreases from 91.4 minutes per person in 1987 to 83.8 minutes per person in 2002, while the potential for dental service remains constant through out the study period at 2267.3 hours and most provided services are retreated patients. In addition, the treatment time for dental diseases increase at a declining rate from 1.42 minutes per person in 1987 to 0.55 minutes per person in 2002. 2. The study of seven alternatives for dental public health problems of 1983 was carried out to compare various consequences of each alternative and the consequence of the business as usual of 1983 trends. Number of personel is increased as targeted by the Ministry of Public Health in Alternative 1, assuming all personel provide full time service. Number of dentist is doubled and of dental nurse is increased four folds from year 1983 in Alternative 2 to 5. Dentists in Alternatives 3 to 5 also work in private clinics after work. The coverage services are emphasized in Alternative 4 and 5 to the maximum. Higher level of preventive and promotive activities are provided in Alternative 5 then Alternative 4. In addition, technology for dental service is more fully developed in Alternative 5 than Alternative 4. number of dentists is increased three folds and dental nurses increased four folds of number of personel in 1983 in Alternative 6 and 7. The differences between these two Alternative are the same as those of between Alternative 4 and Alternative 5. Health officers in Alternative 2 to 7 increase 15 folds (2 health offcers in each subdistrict health office). These officers provide ten percent of their times for basci dental service in these Alternatives. The extra ten percent of their times is also allcocated for the promotion of preventive service and training for primary health care personel in Alternative 4 to 7. The development of technology for dental service is also taken place in Alternative 7. Alternative for 1983 dental public health problem must base on the combined activities of dental treatment and the promotion of self care sheme to the public togesther with the appropriate increase of personel of Altenative 7. It is revealed that this Alternative can produce satisfactory consequences. The average time service need per preson is reduced from 99.9 Minutes per person in 1983 to 31 minutes per person in 2002. Both the increase of personel and change of services in Alternative 7 are more feasible and in harmony with the personel production capacity of educational institutes than all other slternatives. Alternative 1 produces better reduction of the average time service need per person than Alternative 7 but the sheme of personel increase in less feasible to the production capacity than Alternative 7. 3. The analysis of Alternative 7 also shows that the ratio of dentists for community service to population increase from 1 to 47,170 in 1983 to 1 to 26,502, 1 to 19,636 and 1 to 20,366 in 1991, 1999 and 2002 respectively. The ratio of dental nurses in this Alternative also increase from 1 to 47,170 in 1983 to 1 to 26,502, 1 to 18,656, 1 to 14,727 and 1 to 15,275 in 1991, 1999 and 2002 respectively. In conclusion, ratio of dentist and dental nurse to population of Alternative 7 increase to 1 to 20,000 and 1 to 15,000 respectively in 2002.