In this work the polymerization of inorganic polymers synthesized from microsilica and mineral base (KOH or NaOH) was investigated using electro spray ionisation mass spectrometry (ESI-MS). The investigation was conducted in both negative and positive scanning mode enabling detection of both positive and negative charged silicate clusters. Moreover dynamic light scattering (DLS) was used to verify the polymerization model. Similarly, silicate species were identified in the reaction solution of inorganic polymers synthesized from KOH and NaOH. The most intensive peak in the mass spectra was assigned to a dehydroxylated dimer (155m/z). Moreover a range of different silicate species consisting of 3–5 silicon atoms was identified. These species were found most likely to appear in the reaction solution in the form of polyhedras. The evolution in the intensity of the molecule ions in the reaction solution of inorganic polymers showed that the dissolution/polymerization reaction was slower when NaOH was used compared to KOH.