Hi Ajit,
Identifying the root cause of a high CPU load is a difficult process, and requires knowing significant amounts of details about your configuration and perhaps even traffic types and patterns. You have not provided any of these details so we can only give you general guidance.
There are two documents published on the Cisco website that specifically focus on troubleshooting the high CPU issues on 3750 in particular. These are the links - I recommend reading them very carefully, and trying to narrow down the possible cause of your high CPU based on the information in these two documents.
http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3750/software/troubleshooting/cpu_util.html
http://www.cisco.com/c/en/us/support/docs/switches/catalyst-3750-series-switches/68461-high-cpu-utilization-cat3750.html
Best regards,
Peter