<p><em>Effect of four types of diluents</em><em>s</em><em> and four concentration of DMSO (5%, 10%, 15% and 20%) against the motility of African catfish sperm were evaluated after storage at freezing temperatures. </em><em>The steps in preparation the 16 treatments combination of the diluents</em><em> </em><em>are </em><em>preparation of diluents, mixing </em><em>diluents </em><em>with DMSO, packing </em><em>of semen </em><em>in</em><em>to</em><em> 0.3-ml straw, equilibration of </em><em>semen </em><em>at 4 °C for 30 minutes, freezing </em><em>of </em><em>semen in nitrogen vapor liquid </em><em>at </em><em>a height of 6.5 cm for 10 minutes</em><em>,</em><em> and subsequent</em><em>ly</em><em> storage of </em><em>semen </em><em>in liquid nitrogen (-196</em><em> <sup>0</sup></em><em>C) for further analy</em><em>sis</em><em> </em><em>of </em><em>post-thawing motility (PTM). </em><em>The result showed that t</em><em>he highest level of motility of spermatozoa </em><em>was </em><em>in </em><em>treatment </em><em>P</em><em><sub>1</sub></em><em>D</em><em><sub>15 </sub></em><em>(45.7 ± 4.3%) and the lowest </em><em>was </em><em>in </em><em>treatment </em><em>P<sub>2</sub>D<sub>20</sub> (14.5 ± 13.2%). The best diluent </em><em>in </em><em>this observation </em><em>was </em><em>diluents containing NaCl, KCl, CaCl<sub>2</sub> and NaHCO<sub>3</sub>. The best concentration </em><em>was </em><em>DMSO 15%. While the best interaction between the concentration of DMSO diluents is P<sub>1</sub>D<sub>15</sub> treatments containing NaCl, KCl, CaCl <sub>2</sub> and NaHCO<sub>3</sub> with a combination of 15% DMSO concentration. </em><em>The </em><em>conclusion </em><em>of the research is that </em><em>diluents containing NaCl, KCl, CaCl<sub>2</sub> and NaHCO<sub>3</sub> with a combination of 15% DMSO concentration</em><em> can be used in </em><em>cryopreservation of African catfish semen</em><em>.</em></p>