Hierarchically mesoporous silicas could be prepared by means of a previously reported partitioned cooperative self-assembly process (PCSA process) using nonionic triblock copolymer surfactant (P123) as template and sodium silicate as silica precursor. It was found that the partitioning conditions play a key role in inducing the formation of hierarchically mesoporous structures. Under suitable partitioning conditions, in terms of the amounts of sodium silicate in two partitioned additions and interval time between them, the PCSA process allows the preparation of hierarchically ordered mesoporous silicas based on cheap sodium silicate via such a simple templating system, without resorting to additives, multiple templates or complicated synthetic conditions. The size of the first series mesopores is around 9 nm, while the second series of large pores possesses broadened pore size distributions ranging from 20 nm to 200 nm. Under certain partitioning conditions (SS6-4h-4.5 and SS3-4h-7.5), hierarchically mesoporous silicas with the first series of ordered mesopores can be prepared.