In this paper，25 earthquake swarms occurring in Liaoning and its adjacent area since 1970 were systematically studied． The parameter characteristics of the earthquake swarms were summarized，and the relationship between earthquake swarms and the moderately strong earthquake in the future was discussed． The results showed that: ( 1 ) 68% of the largest earthquake occurred within 3 days，84% of the magnitude difference between major earthquake and the maximum earthquake was less than or equal to 0． 5，with the average of 0． 35，and 80% of the earthquake swarms had a duration of 2 months; ( 2 ) the greater the magnitude of the maximum earthquake，the more frequent the corresponding earthquakes of M2． 0 and M3． 0． In general，there were about 28 earthquakes with M2． 0 and 6 earthquakes with M3． 0 in an M4． 0 earthquake swarm; (3) when the frequency of earthquakes with M3． 0，M4． 0 in the earthquake swarms was greater than or equal to 10 and 4 times respectively with the b-value of the sequence being 0． 6 ～ 0． 9，it would be determined as a precursor earthquake swarms． The criterion of three factors of med-strong earthquake in the future was determined as follows: the seismogenic time should be within 1 year (6 months averaged) after the appearance of the earthquake swarms; the epicenter should be located ranging from 0km to 400km ( 180km averaged) of the earthquake swarms; the maximum intensity should be added 2 to the G-R predicted maximum magnitude; when the b-value was less than 0． 5，the earthquake swarms would become foreshock sequence， which means M≥5． 0 earthquake would occur in situ area in 1 day to 20 days after the earthquake swarms; (4) 80% of 25 earthquake swarms were corresponding to M≥4． 6 earthquake after 1 year． The earthquake swarms in Liaoning Inland could provide a good prediction for M4． 6 earthquake in the Liaonan and Tangshan region，while the same method could be used analyzing the earthquake swarms in the waters near Heishan island and Long island for M4． 6 earthquake in the Bohai Strait and its nearby region．