Software Testing Is a Process Used to Identify the Correctness, Completeness, and Quality of Developed Computer Software. It Includes a Set of Activities Conducted With the Intent of Finding Errors In Software So That It Could Be Corrected Before the Product Is Released to the End Users. the Practical Methods Commonly Used to Detect the Presence of Errors In a Program Are to Test It For a Set of Inputs Called Test Case. a Test Case Is a Set of Actions Executed to Verify a Particular Feature or Functionality of Software Application. When Designing the Test Case, the Redundant Test Cases Are Formed That Are of No Use, Increases the Testing Effort and Increase the Cost and Time of Testing. In This Paper, the Goal Is to Reduce the Time Spent In Testing By Reducing the Number of Test Cases. For This the Data Mining Approach of Clustering Technique Is Used In Software Testing to Reduce the Test Suite. Mining of Test Case Will Improve the Efficiency of Software Testing.