This is most likely caused by:

• Vibration of the player during playback.
  • Place the player on a stable surface.
  • If your player has “Electronic Skip Protection (ESP) mode”, activate this mode.
• The Electronic Skip Protection (ESP) running out of buffer time.
  
  After experiencing severe bumps or shocks over an extended period of time, the ESP memory buffer in the player would be empty. This is normal and is not a malfunction. Place the player on a stable surface. When the memory buffer starts refilling, the skipping would stop.

Other possibilities include:

• CD is scratched or CD is sub-quality. If your CD is scratched or of bad quality, the CD would skip. Try to play a good quality disc.
• There is some dust or dirt on the CD. To clean the disc, make sure you wipe the disc in straight lines from the center to the edge. Do not use strong solvents such as alcohol, thinner, petrol or any commercially available cleaner or anti-static spray intended for older vinyl records.