Agavespecies are widely planted for fiber production. However, the molecular basis of agave fiber development has not been well understood. In this study, we performed a transcriptomic analysis inA. amaniensi, a well-known variety with high-quality fiber production. Approximately 43.87 million clean reads were obtained using Illumina sequencing. The de novo assembly produced 66,746 unigrams, 54% of which were annotated in a public database. In the Nr database, 21,490 unigenes ofA. amaniensiswere shown to be most closely related toAsparagus officinalis. Nineexpansin Aorthologs with full coding regions were obtained, which were namedEXP1a,EXP1b,EXP2,EXP3,EXP4a,EXP4b,EXP11,EXP12,andEXP13. The maximum likelihood phylogenetic tree revealed the species-specific expansion ofexpansingenes inArabidopsis, rice and agave. The expression analysis suggested the negative correlation between the expression ofexpansingenes and the leaf growth rate, exceptAhEXP11. Moreover,expansingenes were differentially affected by abiotic and biotic stresses. Notably,AhEXP2expression level was highly upgraded after the infection ofPhytophthora nicotiana. Nutrient deficiency also influentexpansingenes expression. Together, our research will benefit future studies related to fiber development, disease resistance and nutrient usage in agave.