In order to reduce weight of the front subframe， based on engineering practice and ensuring the modal frequency of front subframe can meet engineering requirement， the front subframe finite element analysis model has been established.Modal frequency of the front subframe is simulated and tested， and the modal result simulated by FEA software is simi-lar to that obtained by tests， which also verify the FEA model is credible.In order to reduce weight of the front subframe， the thickness of front subframe is optimized with the modal frequency as constrain condition and the minimum weight of front frame as target， the weight of front subframe is successfully reduced by 13.4%.This study about lightweight of front subframe has certain reference value in engineering practice.