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As the core components of abscisic acid (ABA) signal pathway, Clade A PP2C (PP2C-A) phosphatases in ABA-dependent stress responses have been well studied in <i>Arabidopsis</i>. However, the roles and natural variations of maize PP2C-A in stress responses remain largely unknown. In this study, we investigated the expression patterns of <i>ZmPP2C-As</i> treated with multiple stresses and generated transgenic <i>Arabidopsis</i> plants overexpressing most of the <i>ZmPP2C-A</i> genes. The results showed that the expression of most <i>ZmPP2C-As</i> were dramatically induced by multiple stresses (drought, salt, and ABA), indicating that these genes may have important roles in response to these stresses. Compared with wild-type plants, <i>ZmPP2C-A1</i>, <i>ZmPP2C-A2</i>, and <i>ZmPP2C-A6</i> overexpression plants had higher germination rates after ABA and NaCl treatments. <i>ZmPP2C-A2</i> and <i>ZmPP2C-A6</i> negatively regulated drought responses as the plants overexpressing these genes had lower survival rates, higher leaf water loss rates, and lower proline accumulation compared to wild type plants. The natural variations of <i>ZmPP2C-As</i> associated with drought tolerance were also analyzed and favorable alleles were detected. We widely studied the roles of <i>ZmPP2C-A</i> genes in stress responses and the natural variations detected in these genes have the potential to be used as molecular markers in genetic improvement of maize drought tolerance.