Background: Liver biopsy is a gold standard for the diagnosis of nonalcoholic fatty liver disease (NAFLD), however, it has many limitations. Although many noninvasive tests (NITs) have been introduced for the screening of NAFLD and diagnosing nonalcoholic steatohepatitis (NASH), we developed a simple and novel NITs using artificial intelligence (AI) system for the screening of NAFLD (NASH-Scope) and diagnosing stage of fibrosis in NASH (Fibro-Scope). Methods: 324 biopsy-proven NAFLD patients were recruited for the development of AI systems. For the validation study 74 biopsy-proven NAFLD patients were enrolled who were histologically diagnosed by a central pathologist. NASH-Scope was constructed by age, sex, height, weight, waist circumference, AST, ALT, GGT, cholesterol, triglyceride and platelet count, and Fibro-scope was composed of these eleven clinical items plus type 4 collagen 7s. Findings: NASH-scope differentiated between F0 (NAFL & NASH without fibrosis) and NASH with fibrosis (F1-4) in 99.5% sensitivity, 95.2% specificity, 98.1% PPV, and 98.8% NPV, respectively. In a validation study these were 96.6%, 100.0%, 100.0%, and 85.7%. Differentiation by Fibro-Scope between F0 vs F1-4 was 97.2% sensitivity, 96.2 % specificity, 98.1% PPV, and 94.4% NPV, respectively. In F0,1 vs F2,3,4 they were 98.6% sensitivity, 98.9% specificity, 98.6 % PPV, and 98.9% PPV. In the validation study these were 84.4%, 88.1%, 84.4%, and 88.1%, respectively. The differentiation between F0,1,2 vs F3,4 these were 96.6%,98.7%,96.6%,and 98.7%, respectively. In the validation study these were 89.8%, 80.0%, 89.8%, and 80.0%, respectively. Both Scopes clearly demonstrated excellent diagnostic power for the screening of NAFLD and diagnosing stage of liver fibrosis in NASH. Interpretation: The present AI systems could accurately diagnose NASH and identify NASH with advanced fibrosis. They will take place of histological diagnosis in clinical practice of NASH. Funding Statement: This research is supported by AMED under Grant Number JP19fk0210040 (T.O) and MEXT Grant-in-Aid for Scientific Research (S) Grant number 16H06389 (T.O). Declaration of Interests: All authors have nothing declaration of interests. Ethics Approval Statement: The protocol was approved by each institutional ethics committee at Saiseikai Suita Hospital, and three University Hospitals. This study was performed in accordance with the ethical guidelines of the Declaration of Helsinki, and informed consent was obtained from all patients in each institute before liver biopsy and blood sampling.