Bangonghu-Nujiang suture zone is one of the most important tectonic units in the north of the Qinghai-Tibet Plateau.It was previously considered to be a common phenomenon that the Paleozoic strata were mixed up in the Mescozoic strata as exotic blocks in the west part of the Bangonghu-Nujiang suture zone.This paper aims to introduce the results of biostratigraphic study on the so-called Paleozoic exotic blocks at Wuma in the Tieza-Riyong Mélange Belt where is thought to develop typical phenomenon of strata-mixing in the west part of Bangonghu-Nujiang suture zone and illustrate that it is necessary to strenghthen biostratigraphic research on the exotic blocks in the mélange belt.Methods:In the case of the Tieza-Riyong Mélange Belt,it was thought that the extraneous rocks,the Upper Carboniferous Laga Formation and the Middle Permian Xiala Formation,were mixed up in the Jurassic Mugagangri Group,however,the Xiala Formation was revised to be upper Jurassic Tukari Formation based on the study on the age of corals. Thereafter, it is critical to determine the age of the Laga Formation true or not because it involves that if there are Paleozoic exotic blocks or not in the study area. In this study, sporopollen is utilized to check the age of the clastic rocks Laga Formation and coral is used to determine the age of the carbonate rocks Xiala Formation nearby the observed Laga Formation.Results: First, fourteen species and unidentified species of Mesozoic sporopollen fossils have been found from 9 samples in the strata that were formerly classified as Upper Carboniferous Laga Formation in section A in the Tieza-Riyong Mélange Belt. The sporopollen are Abietineaepollenites sp., Alisporites sp., Anaplanisporites sp., Apiculatisporis sp., Aratrisporites paenulatus Playfor et Detmann, Aratrisporites sp., Asseretospora sp.,Classopllis cf. annulatus (Verbitzka) Li, Cyathidites sp., Gleicheniidites sp., Granulatisporites cf. arenaster Phillips et Felix, Kraeuselisporites sp., Neoraistrickia tayloxii Playford et Dettmann, Plicatipollenites sp. The discovery of these fossils provides paleontological evidence for the revision of the Laga Formation to the Lower Cretaceous Duoni Formation. After this revision, there is no longer the phenomenon of the Laga Formation mixed with Mesozoic strata in the study area. Secondly, in Wuma Substratigraphic Zone of the Gangdise-Tengchong Stratigraphic Zone which is to the south of the Tieza-Riyong Mélange Belt, four undetermined species of Mesozoic sporopollen fossils, i.e. Aratrisporites sp., Cyclogranisporites sp., Leavigatosporites sp., Neoraistrickia sp. were also found in the Laga Formation in section B and 6 species and unidentified species of Mesozoic sporopollen fossils, i.e. Chasmatosporites sp., Ciootiumspora sp., Classopllis cf. annulatus (Verbitzka) Li , Dictyophyllidites sp., Foveosporites sp., Granulatisporites sp. were also found in the Laga Formation in section C in this study. Beyond the discovery of the sporopollen fossils, six species and undetermined species of Late Jurassic coral fossils, i.e. Dermosmilia cf. laxa tallon, Epistreptophyllum sp., Stylina sp., Thamnasteria mettensis Milne-Edwards et Haime , Thamnasteria sp., Thecosmilia sp., were found in the limestone interlayer in the Laga Formation in section B. And late Jurassic Coral fossils, Stylosmilia cf. chauuti Alloiteau and Thamnasteria cf. mettensis Milne-Edwards et Haimeare, were found in the so-called Middle Permian Xiala Formation which is located to the south of section C. According to the above fossils and regional stratigraphic correlation, the so-called Laga Formation and Xiala Formation are respectively revised to be Upper Jurassic Sabozhibule Formation and Tukari Formation.Conclusions:First, the Laga Formation is reasonable to be revised to the Lower Cretaceous Duoni Formation for the discovery of Mesozoic sporopollen fossils in the Tieza-Riyong Mélange Belt. After the revision of the age of the Laga Formation, there is no longer the phenomenon of the Laga Formation mixed with Mesozoic strata in the Tieza-Riyong Mélange Belt. It is necessary to pay more attention on the paleontological research of the unchecked so-called Paleozoic exotic blocks in the mélange belt in the western part of Bangonghu-Nujiang suture zone. Secondly, it reveals that the upper Jurassic is Sabozhibule Formation and Tukari Formation in Wuma Substratigraphic Zone of the Gangdise-Tengchong Stratigraphic Zone by the age revisions of the Laga Formation and Xiala Formation in section B and section C.