[en] The dependencies of relative elongation ε value versus applied stress σ to samples of high (99,9999 mol.%) purity relatively strange (non-hydrogen) impurities parahydrogen (p-H2, approx 0,2 mol.% o-H2) with different (much more or less than) content of stable isotope of hydrogen . deuterium were measured at temperatures 1.8.4.2 K. Samples were tested under step-wise uniaxial extension. The [D]/[H] ration of [D] quantity atoms to protium [H] atoms quantity in p-H2 was (0.0055 +- 0.0005) at.% or that value reached of 0.07 at.%. The disappearance of dislocations light sliding stages from the curves σ(epsilon) and the substantial decreasing of total relative elongation of samples were established. Also, significant increasing of strengthening dσ/dε coefficient value in the case of enriched by the deuterium p-H2 was founded. Moreover, unusual form's changing, which has been determined by the appearance of rotational constituent of low-temperature plastic mass transfer, was observed during deformation p-H2 samples with deuterium atoms far above of natural isotopic composition.