Phonological	change	of	vowel	length	in	Farsi Reza	Heidarizadi* Abstract: There	are	six	vowels	in	the	modern	Farsi.	Generally	it	is	claimed	that	vowel length	is	not	a	phonemic	characteristic	in	this	language.	On	the	other	hand, many	of	the	researchers	show	that	the	deletion	of	glottal	consonants	in	the coda cluster is followed by a compensatory lengthening in Farsi. The purpose	of this	paper is to analyze	minimal pairs	having contrast	only in vowel	length.	Forty	words	were	collected	for	this	purpose.	These	words	are arranged into monosyllabous minimal pairs. It's argued that glottal consonants	are	analogically	deleted in	coda.	This	phonetic	process	causes vowel lengthening.	Hereby,	many	words	are	equally	except	of their	vowel length. This leads to the existence of minimal pairs	with different vowel length. Conclusion is that vowels are under progressing change and probably	vowel	length	will	be	one	of	the	phonemic	features	of	the	vowels	in Farsi. Keywords:	Farsi	vowels,	vowel	length,	Compensatory	lengthening.