A prime concern of the Public Health field, both at a worldwide level and in the middle, low and very low-income areas, is maternal mortality. In this research, it will be presented the dynamic successes in reducing the mortality under 5 years phenomenon. Therefore, Southeast Asia countries have achieved some significant results in decreasing child and maternal mortality over the past two decades. Three out of ten countries that are part of the Association of Southeast Asia Nations Brunei, Singapore, and Malaysia, have infant and child mortality rates below ten per 1000 live births. Within the last two decades, under-5 mortality in Thailand and Vietnam has dropped to below 15per1000 live births, whereas rates in the Philippines and Indonesia have plateaued at 30 to 50per1000 live births. However, Cambodia and Laos continue to have mortality rates of 50–70 per 1000 live births, which are similar to their neighbours' rates from over two decades ago and rank among Asia's highest. There are disparities in diphtheria, polio, tetanus, and measles vaccination coverage, as well as the usage of oral rehydration therapy. Not only Laos has far lower total programming coverage than other countries in the area, but is also far from reaching a 60% coverage level, especially among the wealthier segments. Pediatric care is the most widely available, with coverage near to or above 90% in nations other than Cambodia, particularly in affluent and urban areas. As a consequence, this gap shows that there is room to increase prenatal interventions that can prevent mortality in children under the age of five. Despite the fact that several countries in the region are eligible for funds from the Global Alliance for Vaccines and Immunization, vaccination coverage varies greatly between and within countries. However, many of them have received significant financial and policy support, which is likely to lead to increased vaccination coverage over time. Vaccination rates for Cambodia's wealthiest quintile are comparable to those in other Southeast Asia nations, mirroring those of Indonesia's highest quintile. However, coverage in Cambodia's poorest families is over 40% lower than in the richest households, resulting in a significant vaccination equity gap. Children under the age of five accounted for 70% of mortality among children and teens under the age of 25,accounting for 5.2 million deaths worldwide.The all Nations meet the SDG child survival objectives by 2030.