Arbuscular mycorrhizal fungi (AMF) are found growing within the roots of numerous species of plants and theypenetrate the roots and live asymptomatically. AMF can increase the absorption of essential nutrients for plantgrowth, they also make plants more drought-tolerant and adaptable to harsh environments. Meanwhile, AMF also improves soil structure, by making loamy soil suitable for drainage and aeration. The purpose of this study was to observe and record the diversity of AMF in rice grown in the northeastern part of Thailand. A total of 7 samples of soil and roots were collected from paddy fields. Soil mycorrhizal fungi were detected using the wet sieving method and AMF spores were counted, and their morphological characteristics were recorded and categorized under a stereomicroscope. The results showed that AMF found in Northeast Thailand can be divided into seven groups based on their morphological characteristics. This is a good indicator showing that our soil samples have a rich diversity of arbuscular mycorrhizal fungi and they have the potential to be used as a biofertilizer for Thai rice farming.