A facile and versatile synthesis method, called the partitioned cooperative self-assembly process (PCSA process), is developed to prepare mesoporous SBA-15 silicas using P123 surfactant as template and cheap sodium silicate (SS) as silica precursor. It is demonstrated for the first time that by simply partitioning the cooperative self-assembly process, larger mesopore size (∼10 nm) can be achieved without using any additives or special synthetic conditions; high microporosities (>0.15 cm3 g−1) unprecendentedly persist upon hydrothermal treatment at 120 °C for 20 h with comparable mesopore sizes, which are in big contrast with those prepared by conventional method. The PHTS-type SBA-15s can also be favorably prepared by the PCSA process. In addition, the sizes of flower-like SBA-15 particle can be facilely tuned by adjusting the addition combinations of SS and interval time between the 1st and 2nd additions in the PCSA process. Interestingly, based on TEOS, the PCSA process yielded bimodal mesostructured SBA-15 with different wall thicknesses but the same mesopore size. The versatile PCSA process, which has shown its potential in tailoring the textural and morphological properties of SBA-15s, could lead to even wider spectrum of SBA-15s with various mesostructures if coupled with other synthetic measures.