Micro-cubes of hardened cement paste with the lengths of 100 μm and 200 μm were prepared by micro-dicing and thin-sectioning techniques. The compressive strength and splitting strength of these specimens were measured by a nanoindenter equipped with different types of tips. Considering the heterogeneity nature of the material in a micro-scale, we examined 100 specimens via a statistic analysis. The results show that the two-parameter Weibull distribution can be used to represent the probability distribution of both compressive strength and splitting strength in a micro-scale. The specimens with a higher water-to-binder ratio have a higher strength and a lower variability. Furthermore, the specimen size has an influence on the measured strength. The bigger specimens have lower strength and variability. The reported average value and variability of strengths obtained in this work are greater than those of the concrete in a meso-scale, but lower than those of the hydration product in a nano-scale.@en