Based on outcrop observation and sample collection in the field，the study of developmental patterns and characteristics of interbedded volcanic and sedimentary rocks in the Lower Permian of Zhunnan area was carried out through volcanic petrographic analysis，sample test and indoor comprehensive analysis. The result shows that the volcanic rocks in this area are mainly composed of basic volcanic rocks（basalt）and its associated acidic volcano rocks（dacite porphyry or rhyolite），which would be present as bimodal volcanic rock combination characteristics. Conglomerates and glutenite are mainly developed in the sedimentary rocks. The main components of the gravel are volcanic rocks and pyroclastic rocks，and their composition maturity and structural maturity are relatively low. The sequence of interbedded volcanic and sedimentary rock strata is characterized by alternation of basalt，dacite porphyry and volcanic breccia or sand and mudstone. Six types of lithofacies can be divided as volcanic eruption facies，subvolcanic facies，volcanic effusive facies，alluvial fan fan-root subfacies，alluvial fan fan-middle subfacies and alluvial fan margin subfacies. Four cycles can be divided as neutral cycle，neutral-acid cycle，sedimentary cycle and basic volcanic sedimentary cycle. Under the structural background of continental rift，the basaltic magma formed by the upwelling asthenosphere mantle is melted with the undercut crustal material to become mixed acidic magma，and thus the rhyolite，rhyolite porphyry and basalt were formed，interbedded with the sedimentary rocks formed during the intermittence period after the volcanic activity.