hello yogeshselva, on your android phone go into the system's settings app & into ''accounts & synchronisation'' (might be worded slightly different on different android devices), go to ''firefox sync'' & tap on ''pair a device''. on your desktop go to ''firefox > options > sync > set up firefox sync > i have an account'' which will show you a 3x4 character code that you'll have to enter into your android device in order to complete the process.