A new kaempferol 3-O-(2-β-D-glucopyranosyl)-α-L-rhamnopyranoside-7-O-α-L-rhamnopyranoside and eight known flavonoid compounds were isolated and identified. A biological study includes determination of LD50, anti-inflammatory effect, analgesic effect, ulcerogenic effect, diuretic effect, and toxicity effect. Chenopodium album and Chenopodium murale were found to be highly safe as a drug plant with no serious adverse effect and can be used for curing inflammation and relieving pain.