The original research results for thin disordered HTSC films based on YBCO are presented in this article. Several experiments have been carried out to confirm a theoretical prediction that the s-phase of superconducting pairing in disordered d-type superconductors can occur with a gradual decrease in the mean free path. The YBa2Cu3O7 – x films are used as samples which possess a d-type of superconducting state that was experimentally confirmed. A gradual decrease in the mean free path was achieved by both thermal annealing and ion irradiation. The experiments included measurements of temperature dependence of the London penetration depth λ and resistive studies.