Abstract: In order to study characteristics and the total biomass of the spatial distribution of submerged plants in Lake Erhai, the area of submerged plants were surveyed by the ultrasonic depth finder combined with RTK-GPS and the average biomass were surveyed on different basement. The results showed that the area of submerged plants was 19.40km^2accounting for 7.7% of the whole area of the lake. The submerged plant area distributed in the east, the south, the west and the north accounted for 25.1%, 7.4%, 41.0% and 26.5% of the total area, respectively. The spread basements of the submerged plants ranged from 1959.0m to 1965.0m, while the highest biomass ranged from 2.0to 3.0m in depth. The maximum and the average depth of submerged plants were 6.2and 4.9m respectively. The average value of the maximum distribution depth in the north was the greatest followed by the west and the south, while that in the east was the least among the investigated sites at the four directions. Meanwhile, the decreasing order of distribution width was the north, the south, the west and the east. The biomass of submerged plants reached its maximum value from August to September and the total biomass of whole lake was about 1.60×10^5t.