Pancreatic ductal adenocarcinoma (PDAC) still remains one of the most fatal human malignant tumors. Long-term survival rate is still extremely pathetic even for patients who receive surgery. Epithelial-to-mesenchymal transition (EMT), which is a physiologic process of morphological as well as genetic changes in carcinoma cells, plays a vital role in aggressiveness of PDAC. Meanwhile EMT is also the reason why pancreatic cancer cells achieve such huge metastatic potentials. Many tumor microenvironmental factors such as cytokines, growth factors, as well as chemotherapeutic agents may induce EMT. Our study provides evidence regarding effects of EMT on pancreatic cancer progression, focusing on the correlation between EMT and other pathways which are crucial to tumor progression, especially vitamin D receptor signaling pathway. Research on signal pathways resulting in EMT inactivation during these disease processes may offer innovative ideas on plasticity of cellular phenotypes as well as possible therapeutic interventions.