The cell motility of tumor cells is an integral component of tumor invasion and metastasis. Autocrine motility factor (AMF) stimulates cell motility via a receptor (R)-mediated signal pathway. We studied the correlation between level of AMF-R gene expression by reverse transcription-polymerase chain reaction and cell motility by phagokinetic track assay with or without AMF in lung cancer cell lines. Lung cancer cell lines with higher AMF-R gene expression tended to have greater cell motility than those with lower AMF-R gene expression with or without AMF. Most of lung cancer cell lines showed significantly increased motility with the stimulation of AMF. We conclude that the presence of higher AMF-R gene expression and tumor cell motility via receptor in response to the stimulation of AMF could be an important aspect in the invasion and metastasis of lung cancer cell lines.