Locustella lanceolata has a predominantly Asian distribution, but its breeding range extends just west of the Urals into north-east European Russia. Its European breeding population is relatively small (<100,000 pairs), but was stable between 1970-1990. No trend data were available for the Russian population during 1990-2000, but there was no evidence to suggest that its status deteriorated significantly.

Breeds in upper middle latitudes of (chiefly) east Palearctic, broadly overlapping Pallas's Grasshopper Warbler but ranging up mountains only to c. 800 m and stopping short of main steppe zone. Appears more attracted to wet or moist situations and to presence of bushes and shrubs, although similarly resorting to tall herbage, reedbeds, and tussocky meadows of grasses and sedges, as well as grass and shrubby openings in pinewood taiga or sparser parts of tall forests, and thickets of willow or other shrubbery and sedge surrounding marshes.

In Russia eggs are laid from mid-June. Nest is built on or near ground in thick vegetation, often well concealed in tussock. Nest is a deep, thick-walled cup of dry grass stems and leaves, moss, and other leaves, lined with finer grass. Clutch size 3-5 egss whcih are incubated for 13-14 days.

Diet includes mostly invertebrates like mayflies, grasshoppers, bugs, adult and larval Lepidoptera, caddis flies, adult and larval flies, adult and larval Hymenoptera, adult and larval beetles, ticks, spiders, molluscs. Seeds of herbs also taken.

This species has a large range, with an estimated global Extent of Occurrence of 10,000,000 km². It has a large global population, including an estimated 100,000-200,000 individuals in Europe (BirdLife International in prep.). Global population trends have not been quantified, but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern.

Migratory. Winters south-east Asia south to Greater Sunda Islands, west to northern India and Andaman Islands, east to Philippines. Records in northern Europe almost entirely in autumn (with marked increase since 1973), and extend from Ouessant (north-west France) north to 75°N (125 km north of Bear Island, Arctic Ocean); most are on Fair Isle (Scotland). Autumn occurrences include considerable proportion of juveniles, and presumably result from reversed migration.