In this study, the development of the compressive strength obtained by heat-activation of the mortar produced with Fclass fly ash and sodium meta-silicate was investigated. In the study, mortar samples were produced using F class fly ash, standard Rilem sand and sodium meta-silicate solution. The mortar mixture ratios were taken as sand, fly ash, water 3, 1, 0.466. The amount of sodium meta-silicate was regulated to correspond to 10% of the fly ash content of the amount of sodium to be put into the mixture. Mortar workability test was carried out on fresh mortar. The workability of fresh mortar mixtures is measured as 200 mm. Prismatic samples of sizes 40x40x160 mm were prepared from fresh geopolymer mortar mixtures. The geopolymer mortar mixture was subjected to initial heat curing at 75 ° C for 24 hours. After the initial heat curing, some of the samples were continuously cured in the laboratory condition and flexural and compressive strengths were measured at specific intervals up to six months. The unit weight of the solidified geopolymer mortars is around 2.3 gr / cm3. The flexural and compressive strengths obtained from the samples are given in Table 1. When Table 1 is examined, it is shown that after 75 degrees C heat curing for 24 hours 45 MPa is obtained. It has been seen from the table 1, after 75 C heat curing for 24 hours, 45 MPa compressive strength is obtained. It is understood that the samples cured in the laboratory condition after heat curing continue to improve their strength. In the case of additional curing for 6 months, the compressive strength is 62.3 MPa. After six months it is found that the compressive strength approximately 40% higher than one day's strength. In the flexural strengths, an increasing tendency was observed over time, but no regular increase was recorded. When the flexural strengths were evaluated as value, all samples showed bending strength of 10 MPa and over.