In this study, we primarily select the author′s research to briefly introduce the various superconducting materials that are synthesized using high pressures. Superconducting systems included are ranging from cuprates, iron-based materials, to topological compounds. They are fabricated using: ″self-high-pressure oxidization″, which is produced using the chemical composition of the synthesized material itself rather than using traditional alien oxidizers; ″inner pressure effects″, which are generated using the atomic size changes; and a ″pure doping mechanism″ that is induced using a pressure-induced charge transfer, respectively. We focus on three categories of superconductors in our investigation. (1) Apical oxygen ordered cuprate superconductors that reach the highest T c for the monolayered cuprate superconductors, Cu12( n −1) n homologues series cuprate superconductors having a T c of up to 123 K, and a Cl2( n −1) n homologues series cuprate superconductor that is the first halogen-containing superconducting system having a T c higher than liquid nitrogen: These cuprate superconductors comprise only copper and alkaline earth metal oxides, which are the simplest reagents that are necessary to form high T c cuprates. However, those high pressure synthesized materials exhibit very high T c that usually can only be realized in cuprates superconductors with complex compositions if prepared at ambient condition such as YBCO123, Bi22( n −1) n , or Hg12( n −1) n . The new superconductors exhibit excellent critical electrical current density as a function of temperature, especially at high temperatures. They show superior properties than the Bi/Hg cuprate homologues superconductors and are comparable to the classical Y123. (2) The ″111″ iron-based superconducting system: This system features neutral-charged cleaved fresh surfaces that are perfect for experimental studies based on angle resolved photoemission electron spectroscopy (ARPES) or scanning transmission microscopy (STM). Compared with other important iron-based superconductors, this unique feature facilitates the unambiguous detection of intrinsic properties without surface reconstruction. Studies on LiFeAs, which are representative members of the ″111″ system, reveal the non-Fermi surface nesting characteristics that are in sharp contrast to the observations in previous iron-based superconducting systems. This study indicates that Fermi surface nesting is not necessary for the generation of superconductivity in iron-based materials. This is a critical step to understand the mechanisms of iron-based superconductors. (3) Pressure-induced superconductivity in the topological compound Bi2Te3: this is the first superconductor in a topological compound generated by applying pressure and without using chemical doping.