The aim of this reaserch is to prepare composite samples of nylon 6 / nanoclay, alloy samples of nylon 6 / polyethylene grafted with maleic anhydride and a hybride of above as a substitute for nylon 12. Nylon 6 is an engineering plastic and in this research the aim is to change its mechanichal properties and gasoline permeation resistance that can be used instead of nylon 12. For this aim, first two types of compound include composite samples of nylon 6 / nanoclay and alloy samples of nylon 6 / polyethylene grafted with maleic anhydride(PE-g-MA)prepared with melt method. For evalution of properties of samples, three type tests were carried out.Once type of test were include X-Ray diffraction analysis (XRD) and Thermogravimetry analysis (TGA) on samples of composite were carried out. Second type, Scanning Electron Microscope (SEM) and FTIR analysis were carried out alloy on samples. Tertiary type, gasoline permeation, tensile strength, elastic modulus, strain to failure and impact strength carried out on two type samples. Cloisite 30B was used in composite samples. In nylon 6/ nanoclay composites was used with weight percents of 1, 3 and 5. TGA analysis show that real amount of nanoclay in composite for samples with 1, 3 and 5 weight percent was 0.95, 2.86 and 4.75 respectively. XRD analysis shows that peak available in cloisite 30B in 2? = 4.8, did not appeare in samples with 3 and 5 weight percents. Results show that nanoclay exfoliated in nylon 6. Also, the alloys of nylon 6 /PE-g-MA were prepared with weight percents of 10, 20 and 30 of PE-g-MA. FTIR results show that, there was interaction between maleic anhydride group in PE-g-MA and amide group in nylon 6. SEM photomicrographs show that separated phase in alloy samples not seen.Results of gasoline permeation show that, the lowest gasoline permeation occurred when using 3 wt% of nanoclay (0.46 gr/m 2 .day) in composites and 10 wt% of PE-g-MA in alloys(0.46 gr/m 2 .day). Moreover, the tensile test results showed that with increasing the amount of nanoclay from 1 to 5 wt% in composites, the elastic modulus increased by 18 to 45% and tensile strength increased by 12 to 47% with respect to neat nylon 6. While, in alloys with increasing the amount of PE-g-MA from 10 to 30 wt%, the elastic modulus decreased by 7 to 31 % and tensile strength decreased by 14 to 42% compared to neat PA6. Also, the results of impact test showed that the impact strength ofcomposites increased with increasing the amount of nanoclay decreased and impact strength alloys increased with increasing the amount of nanoclay and PE-g-MA. Finally sample with 3% nanoclay and 10% PE-g-MA prepared and mechanical properties and permeation resistance were investigated. The result of permeation test shows that this sample had lowest amount of permeation when compared with composits and alloy samples (0.41gr/m 2 .day). Tensile test results for composite- alloy sample showed that, the elastic modulus increased 9%, tensile strength decreased to 10%and impact strength increased to 97% respect to neat nylon 6. Keywords: nylon 6, composite, alloy,gasoline permeation, mechanical properties