The present invention relates to a transparent polyamide-imide resin and a film using the same and, more specifically, provides: a polyamide-imide resin which is colorless and transparent, shows excellent thermal stability and mechanical properties, and has improved birefringent characteristics such that the polyamide-imide resin is useful in various fields of a semiconductor insulator, a TFT-LCD insulator, a passivation layer, a liquid crystal alignment layer, materials for optical communication, a protective film for a solar cell, a flexible display substrate and the like; and a film using the same.