The purpose of this study aimed to find the incidence of perinatal mortality rate, characteristics of perinatal mortality as well as maternal, fetal and service factors related to the duration of perinatal death The study was conducted in 44 provinces of Thailand i.e Angthong, the province in the Central region, all provinces in the Northeast, 13 provinces in the North (exclude Chiang Mai, Lampoon, Uttaradit and Sukhothai) and 13 provinces in the South (exclude Suratthani) The data were collected during October 1, 1989 - September 30, 1990 There were perinatal death 4.144 cases The data analysis was done in tern of rate, percentage and was presented by crosstabulation. The result showed that their were 16% of perinatal mortality which their others were less than 20 years old, and 18% were more than 35 Host cases were in the Northeast About 10% did not receive antenatal care from health personnel and deriveried by other person than health personnel especially in the South. Incidence rate of intra-partum mortality rate was high in the South and the same rate of pregnant women group did not receive antenatal care or received less than 4 times visited. Half of cases were the first baby and low birth weight (less than 2500 grams.). The overall perinatal morlatity rate (PNR) was 8.8 per 1000 births, of which PMR in Angthong province, the Northeast, the North, and the South were 5.0, 10.1, 9.9 and 5.7 per 1000 birth respectively. The province with the hightest of PMR in the Northeast, the North and the South were Loei (16.8) Tak (22.3) and Yala (18.6) province per 1000 births respectively. The characteristics of PMR were the pattern of developing countries i.e. the major characteristics were macerated 31% , birth asphyxia 25% , pre-maturity 20% ,congenital anomaly 14% and other specific condition 10% . The pattern was the sane in all the region. The duration of perinatal death identified to be Prenatal death,Intra-partur and Early neonatal death with the factors related : maternal, fetal and service using factors showed that the fetal whom their mothers did not receive antenatal care has higher proportion of Prenatal death than the others in all regions.