The purpose of this study is to investigate the effect of liquidity on profitability Iran Khodro automobile company. This study has used the Bounds test and Autoregressive Distributed Lag (ARDL) models during 1375-1389 .In this study is used in addition to traditional measures of liquidity, such as the current ratio and quick ratio. The new measures include a new comprehensive liquidity index, the index was adjusted, the index of net cash and cash conversion cycle eventually unadjusted index.  In this regard, have been used to control other variables that affect profitability such as financial leverage and GDP. According to the results, that the use of new and innovative liquidity more appropriate indexes is to examine the relationship between liquidity and profitability.The use of a weighted average and periods of receivables and current liabilities and as well as the balance of cash and securities and cash conversion cycle in the new indexes calculation than traditional indexes suggest that in the experimental studies used from new indexes of liquidity than traditional indexes.