Abstract: ZSP1601, a novel pan-phosphodiesterase inhibitor is in development for the treatment of nonalcoholic steatohepatitis. A physiologically-based pharmacokinetic (PBPK) model was developed to predict the pharmacokinetics of ZSP1601 in human. The PBPK model following intravenous and oral dose of ZSP1601 in rats and dogs was firstly built using preclinical in vitro and in vivo data. The PBPK model in human was then built based on models in animal. The in vitro.in vivo extrapolation (IVIVE) method and some allometric scaling methods were used to predict the clearance in human, respectively. The PBPK models using IVIVE and allometry of unbound CL plus the rule of exponents methods predicted the pharmacokinetics of ZSP1601 in healthy Chinese subjects successfully. The predicted parameters C_max and AUC following single oral dose administration were within 0.5-2 folds of the observed data. The model was optimized and the final model was used to predict the pharmacokinetics of ZSP1601 in North European Caucasian, Geriatrics, Obese and Morbidly Obese, respectively. Animal studies were approved by the Animal Management and Use Committee of Suzhou AppTec Inc., and the approved No. is SZ20140916.