This aims of paper are to investigate the utilization of natural pozzolans as cementitious materials. The mix proportions used in the study were designed in 4 series. In series 1, this study presented the usage of perlite in lightweight concrete. The perlite in this study is perlite type III, is a type of mineralogical material containing large quantities of reactive SiO2and Al2O3, small particles, high porosity and lightweight. In the study, used the perlite to replace sand and cement at ratio of 0, 10, 20, 30, 40 and 50% by weight of binder. Comparison of the compressive strength and density of perlite mortar was performed with control mortar at in range of 105 to 115 %. In series 2, this study presented workability and compressive strength of fly ash based of geopolymer mortar containing diatomite as binder replacement at the rates of 0, 60, 80, and 100% by weight. Sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) solutions were mixed together and then used as a liquid portion in the mixture in order to activate the geopolymerization. The ratios between Na2SiO3 and NaOH were varied, namesly, 0.5, 1.0, 1.5, 2.0, and 2.5 by weight whereas the ratios between liquid binder of 0.40, 0.50, 0.60, and 0.70 by weight were varied. The additional water was added to improve the workability of fresh geopolymer mortar. The ratios between additional water and binder were varied, that is to say, 0, 3, 6, 9, 12, and 15% by weight. In additional, the NaOH concentration of 5M, 10M, 15M, and 20M were also used as variables. Each mixture was separated and cured in the oven at the temperature of 60oC, 75oC, and 90oC for 24 h. Flowability of all fresh geopolymer mortars were investigated and the compressive strength test was applied at the ages of 7, 14, and 28 days. In series 3, the property of solidified wastes using OPC containing synthesized zeolite (SZ) and natural zeolite (NZ) as binders. Zeolites were used to partially replace OPC the rate of 0, 20, and 40% by weight. The plating sludge was used as contaminated waste to replace binder at the rate of 40, 50 and 60% by weight. The water to binder (w/b) ratio of 0.40 was used for all mixes. Setting time and compressive strength of solidified wastes were tested and leachability of heavy metals were determined by TCLP. In addition, XRD, XRF, SEM of fractured surface and pore size distribution by MIP were investigated. Finally in series 4, This study presents the effect of palm oil fuel ash fineness on microstructure of blended cement paste. Palm oil fuel ash (POA) was ground by ball mill with 2 types of different finenesses. Ordinary Portland cement (OPC) was partially replaced with ground palm oil fuel ash at the rate of 20% and 40% by weight of binder. The water to binder ratio (w/b) of 0.35 was used for all mixes. The amorphous of ground palm oil fuel ash by Rietveld method, compressive strength, thermogravimetric analysis, pore size distribution of blended cement paste were investigated. The results in series 1 revealed that the perlite specific gravity was 0.50, the increasing quantity of perlite were direct effected to increase setting time and decrease compressive strength. The use of perlite of 50% cement replacement at 28 days obtained compressive strength and density were 101 kg/m2 and 1,460 kg/m3 respectively. And using perlite of 50% sand replacement gave the compressive strength and density were 59 kg/m2 and 990 kg/m3 respectively. Test results in series 2 revealed that the mixture having Na2SiO3/NaOH of 1.5-2.5, 15M of NaOH concentration, and 75oC of curing temperature showed compressive strength between 223-939 kg/m2 which high enough for using as normal strength concrete. Moreover, additional water could improve the workability of fresh geopolymer mortar, however, the compressive strength reduction could be observed. Additionally, the compressive strength of geopolymer mortar increased obviously at early age, however, at the later age it was slightly increased for some mixtures. Furthermore, the replacement of diatomite at the rate of 60 and 80% by weight were well suited for both compressive strength and workability. Test results in series 3 indicated that the compressive strength of all solidified wastes made with 40, 50 and 60% by weight of plating sludge was decreased as compared to those samples without the wastes. TCLP results showed that concentration of heavy metals in leachates weren’t exceeded the limit specified by US.EPA. SEM and MIP results revealed that the solidified wastes became denser and the replacement of Portland cement by zeolite increased the total porosity but decreased the average pore size. Finally in series 4, Test results indicated that the ground palm oil fuel ash was amorphous silica material. The compressive strengths of cement paste containing POA fineness were as high as that of OPC cement paste. Paste containing 20% of POA with high fineness had the lowest total porosity. Ca(OH2) contents of cement paste containing POA decreased with the increasing replacement of POA and was lower than that of the OPC cement paste. In addition, fineness of POA had an effect on the reduction rate of Ca(OH2). Furthermore, the critical pore size and average pore of cement paste containing POA was lower than the OPC cement paste.