Capillary electrophoresis with sieving polymer solution proves the efficiency in separation of short and middle-sized genetic fragments (usually shorter than 1000 bases or bp).For longer fragments, or strong electric field that favors high speed separation, the velocity of oriented DNA/RNA chain is size-independent in direct current (DC) field CE.Pulsed electric field was introduced to resolve this problem.Research to improve the understanding of properties and mechanisms of long fragments migration and separation under pulsed-field is still underway.In our study, systematic experiments were carried out to investigate the regulation of long DNA/RNA fragments migrating and separated under pulsed electric field.