In this study, the effects of melt structure (tuned by controlling the fusion temperature T-f) on non-isothermal crystallization and subsequent melting behaviors of isotactic polypropylene (iPP) nucleated with / compounded nucleating agents (/-CNAs) have been further investigated. The results show that under all cooling rates studied (2-40 degrees C/min), the crystallization temperature on cooling curves increased gradually with decrease of T-f, meanwhile, when T-f was in temperature range of 166 degrees C-179 degrees C where ordered structures survived in the melt (defined as Region II), crystallization activation energy E was found to be evidently lower compared with that when T-f > 179 degrees C or T-f < 166 degrees C. The results of subsequent heating showed that occurrence of Ordered Structure Effect can be observed at all the cooling rates studied; the location of the Region II was constant when cooling rate varied; Low cooling rate encouraged formation of more -phase triggered by ordered structure. Moreover, the role of ordered structure on - recrystallization was comparatively studied by tuning the end temperature of recooling (T-end) after held at T-f, and it was found that ordered structure encouraged the formation of -phase with high thermal stability at low temperature part of Region II, while enhanced the -crystal with relatively low thermal stability at high temperature part of Region II. POLYM. ENG. SCI., 57:989-997, 2017. (c) 2016 Society of Plastics Engineers