PYCR1 is over-expressed in non-small-cell lung cancer (NSCLC) and its high expression accelerates the progression of NSCLC. However, the underlying mechanisms of PYCR1 in NSCLC progression remain poorly understood. Our study determined the mechanisms of PYCR1 in promotion of the occurrence and development of NSCLC in vitro and in vivo. Firstly, the expression patterns of PYCR1 in NSCLC tissues and cells were determined by RT-PCR, western blot and immunohistochemistry. Then, the effects of PYCR1 on cell proliferation and apoptosis were evaluated by CCK-8 and flow cytomery assays. Finally, we explored the up-regulatory microRNAs (miRs) of PYCR1 and determined if MAPK pathway involved in this process. PYCR1 expression was elevated in NSCLC tissue samples and cells, and the high expression of PYCR1 closely associated with patients’ advanced clinical process and poor outcome. Up-regulation of PYCR1 significantly increased the expression of p38 and promoted its nuclear accumulation. Besides, PYCR1 expression was negatively regulated by miR-488, and up-regulation of miR-488 significantly inhibited cell proliferation and tumorigenesis and increased cell apoptosis, and decreased p38 expression and its nuclear accumulation, whereas up-regulation of PYCR1 rescued these results induced by miR-488 over-expression. Collectively, these data suggest the mechanism of PYCR1 in promotion of NSCLC progression. PYCR1 is negatively regulated by miR-488 and then promotes the occurrence and development of NSCLC and activates p38 MAPK pathway.