Internet Of Things (IOT) Based Home Security System: Security Is The Main Concern Of The World Now Days. Sensor Based Home Security System Are The High Technology And Methodical Systems Which Connect Wirelessly And Ensure Real Time Operation And Indication Of The Threat To The House. The Idea Of Comfortable Living In Home Has Changed Since The Past Decade As Digital, Vision And Wireless Technologies Are Integrated Into It. Now-a-days Internet Plays A Major Role In Every Area, So Integrating Sensors Technology With An IOT Environment Could Resolve The Security Issues Of Society To A Great Extent. The Various Drawbacks Of Existing Technologies Are Cost And Range. In This Paper A Design And Implementation Of Sensor Based Security System With An IOT Environment Has Been Presented, Which Will Resolve Various Security Issues Like Unauthorized Intruder Entry, Fire Detection Etc. Therefore Continuous Monitoring Of The Home/apartment Is Possible. The System Is Cost Effective, Reliable And Has Low Power Consumption.