The pharmacokinetic(PK) of drugs and its parameters are different among pediatrics, children and adults due to physiological differences such as body size, maturation of organs.Since population pharmacokinetics modeling of adults is hard to be applied directly to pediatrics, the modified model for pediatric is required to explain the variability in pharmacokinetics of drug.The aim of this study is to review current trends and techniques of population pharmacokinetics studies in pediatrics and evaluate potential possibility of those methods as improved approaches for explanations of variability in pediatrics.In the recent, the allometric and physiological scaling method between covariates and maturation (e.g., age) based on population approaches have been appeared as a good alternative method for explanation of PK/PD in pediatrics.The most affected physiological condition to clearance and volume of distribution in pediatrics theoretically was body size which is involved in allometric scaling and maturations of organ functions depending on aging.Therefore, size functions and maturations functions put into population model additionally using allometric equation and sigmoid hyperbolic equations for explanations of change of organ maturations, respectively.It can improve the unexplained variability especially within 4 weeks of age and was also useful under 1 years of pediatrics in describing maturation process.In case of the pediatrics over 1 years old and children, population approaches with allometrics scaling alone, as size function, was suitable explained for above because those ages had similar organ functions in comparison with adults.Therefore, it is better to reflect on pediatric pharmacokinetics modeling using both methods than to use general population modeling for adults.In conclusion, covariate analyses and modeling of pediatric data result in optimization of drug for children with different ages, body weights.In further study, we will develop the pediatric PK model with every approach in several drug and will suggest best approach for pediatric.