Cyclin-dependent kinase Cdk1 is the master regulator on eukaryotic cell cycle control and crucial for prevention of genomic instability. Given its essential function in cell cycle progression, Cdk1 is tightly regulated. Among others, CDK inhibitors (CKIs) are important negative factors for CDK activity regulation, lack of which leads to uncontrolled cell division and promotes tumorigenesis. The model eukaryotic organism Saccharomyces cerevisiae, budding yeast, in many respects is an ideal organism for eukaryotic CDK regulation research. In budding yeast three Cdk1 inhibitors are known: Far1, Sic1 and recently identified Cip1. Apart from inhibiting Cdk1 activity during cell cycle progression, CKIs also play crucial roles to maintain genomic stability in response to environmental stresses. This paper reviewed the researches on Cdk1 inhibitors, especially their functions on cell cycle progression and stress responses, to provide a model basis for cell cycle and cancer fundamental research.