Morphological evolution from SnO2 quantum dots (QDs) to quantum chains (QCs) confined in channels of mesoporous silica (MS) has been studied systematically in this work by varying the nuclei quantity deposited on the channels inner surface under hydrothermal conditions. Decreasing the MS amounts could influence the nuclei quantity and the subsequent crystal growth as well as the assembly process to form QCs by oriented attachment inside the channels. It is interesting to find that the evolution of SnO2 QDs -> QCs systems would induce the variation of strain type tolerated, simultaneously, from tensile to compressive strain, and also exhibit morphology-dependent photoluminescence properties.