A low dusting powdery alginate impression material for dental use is disclosed which comprises:(a) an alginate,(b) a gelling agent,(c) a gelation controlling agent,(d) a filler,(e) at least one hydrophobic liquid having a vapor pressure of not higher than 3.15 mmHg at 20.degree. C. selected from the group consisting of a hydrocarbon and a silicone oil not containing a hydrophilic group,(f) polyvinylpyrrolidone, and(g) at least one compound selected from the group consisting of oxides, hydroxides and fluorides of metals.With the alginate impression material, gypsum models prepared using the negative mold of an impression have high surface precision and impressions of oral cavity having high precision can be obtained as well as substantially no dust formation is observed when taken out of a storage container and during mixing with water.