Background: The aim of this study was to explore the effect of baicalein on diabetic cardiomyopathy (DCM) rats and the mechanisms involved, and to determine the theoretical basis for clinical anti-tumor therapy. Material/Methods: DCM rat model was induced with a single injection of streptozotocin. Then, DCM rats were treated with baicalein alone or co-treated with baicalein and PI3K/Akt inhibitor. Myocardial pathological changes were detected by HE and Masson staining. The activities of SOD, GSH-Px, and MDA in myocardial tissue were measured by biochemical tests. The levels of TNF-alpha, IL-1 beta, and cTn-l were examined by ELISA. NADP+/NADPH ratio was measured with the NADP+/NADPH assay kit. RT-PCR was used to detect the levels of PI3K and Akt. The levels of Bax, Bcl-2, Caspase-3, GSK-3 beta, PI3K, and Akt were detected by Western blot. Results: Baicalein could improve pathological injury. SOD and GSH-Px activity decreased while the level of MDA increased in myocardial tissue. Baicalein treatment enhanced SOD activity in a dose-dependent manner but markedly reduced MDA. Similar changes were observed in both serum inflammatory factors and the NADP+/NADPH ratio. After adding PI3K-Akt inhibitor, the levels of PI3K and Akt mRNA expression were significantly decreased, but were not significantly different from the DCM group. Levels of Bcl-2, PI3K, p-GSK-3 beta/GSK-3 beta, and p-Akt were decreased in the DCM group, while the levels of Bax and Caspase-3 were obviously increased. Conclusions: Baicalein can protect DCM rats against damage from oxidative stress and inflammation in myocardial tissue, and PI3K/Akt signaling pathway may be involved to mediating these effects.