From 24 investigated Supernova remnants 12 the HI envelopes with radial motions are found. The example of an envelope around the Supernovae remnant W28 is shown on figure 1. Mean velosity of radial motion is 12.9 km/s, thickness of envelopes is 0.3 of radius, mean HI mass is 5.6E+4 mass of the Sun, mean kinetic energy is 10⁵⁰ ergs. Ages of the remnants, initial energy of explosion, times of the beginning radiative phase etc. are calculated under these data. It is necessary to notice, that presence of an HI envelopes testifies, that the remnants are in the radiative phase and no one of them does not produce X-ray.

Figure 1. Distribution of HI emission around the Supernovae remnant W28. The details shows an extending envelope.