According to different grammatical meanings, modal particles in Lujiang dialect are divided into three categories: Event modal particles, attitudinal modal particles, and interrogative modal particles. The modal particles in Lujiang dialect have distinct characteristics, with four main features: the total number is more than that in Mandarin; the modal particles used in declarative sentences in Lujiang dialect are less than those in Mandarin, indicating that people in Lujiang do not like to express emotions in a flat tone, and are prone to use changing rising or falling tones to convey mood; there is not a one-to-one correspondence between modal particles and moods in Lujiang dialect. The same mood can be expressed by different modal particles, and different moods can be expressed by the same modal particle, showing great flexibility; the modal particles in Lujiang dialect maintain a high similarity with the Jianghuai Mandarin (the region in which Lujiang is located), but some modal particles are unique, showing relative independence. The origin of some modal particles in Lujiang dialect was examined, and their grammaticalization paths were pointed out.