Effective mobilization of deposit plays a key role in keeping up the safety and reliability ofrnfinancial system in general and commercial banks in particular. The general objective of thernstudy is to investigate the determining factors of deposit mobilization of private commercialrnbanks in Ethiopia by using a balanced panel data of 10 private commercial banks from 2009 torn2018. In preparing this research only secondary information has been used. The secondary datarnwould be obtained from annual report of National Bank of Ethiopia and audited financialrnstatements of sample private commercial banks. Explanatory research approach, with arnquantitative research method was used to establish the causal effect relationship betweenrndetermining factors (variables) and deposit mobilization of private commercial banks. Sixrndetermining variables (deposit interest rate, government expenditure, money supply, inflation,rnliquidity ratio and return on asset) as explanatory variables have been used for the study. Forrnthis study the researcher has used a purposive sampling technique from which 10 (ten) privaterncommercial banks, which would provide and had complete ten year data, have been selected.rnThe analysis process applied a quantitative technique of data presentation using tables andrnpercentages. The investigation result using pooled OLS estimator reveals that, Inflation,rngovernment expenditure and return on asset have negative relationship with deposit growth ofrnprivate commercial banks, while money supply, interest rate and liquidity ratio have positivernrelation with deposit growth of private commercial banks. Based on the findings and conclusionrnthe researcher recommends that the liquidity management team of the bank should manage andrnsupervise amount of asset which should be held as liquid assets so as to enhance depositrnmobilization of private commercial banks