Plant-derived protein hydrolysates have been considered promising substitutes for serum in mammalian cell growth cultures. We selected a few growth promoting protein hydrolysates (Broadbean, Soy F, and Soy P) and made mixture compositions with those hydrolysates, which considerably improved the growth and viability of Chinese hamster ovary (CHO) cells. We also investigated the effects of both individual ultrafiltered fraction of protein hydrolysates and mixture composition with the fractionated hydrolysates, and found that some of the mixture compositions containing fractionated hydrolysate with a small fraction of a high-molecular-weight hydrolysate supported a cumulative cell count equal to or slightly greater than that observed in the control media containing unfractionated hydrolysates. It is believed that such medium composition is beneficial for downstream processing of protein production due to a cleaner broth. We conclude that CHO cell growth and viability may be improved in media containing a mixture of unfractionated or fractionated plant protein hydrolysates compared with media containing a single hydrolysate.