1. Muddy coast is widely distributed in Tianjin littoral zone.

2. The littoral zone of a sea is the part of the sea between high and low tide marks.

3. Most navigable waterways require dredging because of siltation. This is true when navigation penetratethe littoral zone.

4. The distributions have a close relation with bed rock property, littoral zone types, geography, water systems, hydraulic conditions and bed property of sea bottom.

5. And this has already been an inevitable trend of history development. The question of "land deficit" exists in the littoral zone area of high density of population.

6. The present dissertation is a systemic study on marine microorganisms in plant habitats of southward and northward littoral zone.

7. Most navigable waterways require dredging because of siltation. This is true when navigation channels penetrate through the littoral zone .

8. Objective To study the effect of lower temperature in winter on the development of of Anopheles sinensis in the littoral zone of Guangdong.

9. It gives a mark to each index of sustainable development of littoral zone through the questionnaire and form visited, gets the weight of each index and the results of seven cities finally.