How 2 trace a laptop with its serial number

please give me answer of my my question

You need to contact the police. There isn't a way to track a stolen laptop if you didn't have tracking software on the laptop before it was stolen.

The serial number of a laptop isn't visible over the internet. So it can't be tracked.

The only useful thing the serial number can do is trace ownership back to you - but only AFTER it's been recovered by someone willing to check it out. Like Law Enforcement.
Or possible a laptop repair facility.

File a stolen property report. Notify the laptop manufacturer.