Experiments are performed for comparative study of heat transfer performance of twisted tape inserts in evaporation of R407C in a plain horizontal copper tube of13.39 mm inner diameter and 2 m length. Experiments are conducted with operating conditions of: (i) evaporating pressure - 3.5 to 7 bar; (ii) heat flux - 1.33 to 9.1 kWm-2 ; (iii) mass flux - 100 to 300 kg s-1 m-2. Vapor quality in test section is varied from 5 % to 95%. Three twisted tapes of twist ratio y= 8, 10 and 12 are used for comparative study.The main objective of this comparative study is to understand the behavior of flow boiling heat transfer coefficient against vapor quality for different twist ratios and heat transfer performance of twisted tapes with these twist ratios. Twisted tapes are more effective for enhancement of heat transfer within lower vapor quality region of 10% to 50% only. Twisted tape-III with twist ratio, y= 12 is the best heat transfer performer and twisted tape-II with twist ratio, y =10 is the second best heat transfer performer. In general, heat transfer performance of twisted tape depends on its geometry and operating conditions. Keywords: Heat transfer enhancement; investigation; refrigerants; R407C; twisted tapes.