中文摘要：

河型研究是河流动力学及河流工程学中的一个基本问题，也是沉积学家判别地下不同成因砂体的一个关键问题。目前河型的分类大都基于河流的平面形态，而这一分类受到了越来越多的质疑，并提出了一些新的分类方案，许多研究者注意到河型并不是离散的，存在一系列连续变化的河型，同时，顺直河、曲流河以及辫状河这些常见的河型之间可能发生突变，河型转化是当前国际河流学界研究的前缘和薄弱环节。本文通过综述河型转化在现代沉积、模拟实验、露头以及地震四个方面的研究进展，认为河型转化主要受到构造作用、沉积物供给、气候条件和海（湖）平面变化四大因素控制，其中前三个因素对于古河型的演化至关重要。在上述因素的影响下，一条河流从上游往下游，往往具有由辫状河——一低弯度曲流河—一高弯度曲流河—一网状河的演化规律。但是河流的位置并不是决定上述变化的主要因素，只要符合条件，即构造作用、沉积物供给及气候等因素发生重大变化的情况下，河型就可能发生转化。然而，河型转化的研究成果尚未引起石油地质学家们的足够重视，并没有被充分的应用到古代河流的解释中去，这将是今后的一个重点研究方向。

英文摘要：

Fluvial pattern is not only a basis problem in river dynamics and river engineering, but also a key problem for sedimentologists to identify different types of sandstone. Currently, most classifications of fluvial channels are based on the plan-view morphology and while these classifications have received more and more criticism, and a great many new classifications are proposed. A number of researchers recognize a continuum of channel forms rather than discrete types, while others see abrupt transitions between straight, meandering and braided channels. Fluvial pattern transformation is becoming the leading edge and weak point of present sedimentology. In order to direct hydrocarbon exploration, based on reviewing the latest research progress in modern deposits, simulation experiment, outcrops and seismic study, the rule and controlling factors of fluvial pattern transformation were discussed, and some problems and corresponding countermeasures were proposed. The results demonstrate that the fluvial pattern transformation is mainly controlled by tectonic activities, sedimentary supply, climate condition and sea （lake） level change, and the former three factors are more important for ancient fluvial pattern transformation. Infuenced by the above factors, from upstream to downstream one river usually changes from braided river to low sinuosity meandering river, high sinuosity meandering river and anastomosing river. However, the location of river is not the main factor to determine the transformation, as long as meeting the conditions, such as tectonic activities, provenance supply and climate abrupt change, and the fuvial pattern may transform. However, the petroleum geologists have not paid much attention to the researches of fluvial pattern transformation, which have not be used to interpret ancient fluvial deposits, and this will be a focus of future research directions.