The concept of blockchain as a standalone technology started gaining popularity in 2015. Prior to that, it was just known as a data structure underlying Bitcoin technology. Bitcoin’s rise into popularity resulted in it being categorized as Blockchain 1.0. With Ethereum making waves as a decentralized platform for applications that run exactly as programmed, more and more people began to categorize Ethereum as Blockchain 2.0. Now the market is battling to see who will be named Blockchain 3.0. Direct Acyclic Graph or DAG may be it. BlockDAG – In the context of distributed ledgers, a blockDAG is a DAG whose vertices represent blocks and whose edges represent references from blocks to their predecessors. DAG ( Directed Acyclic Graph) is a directed graph data structure that uses a topological ordering. The sequence can only go from earlier to later. DAG is often applied to problems related to data processing, scheduling, finding the best route in navigation, and data compression. The first community to come up with the idea of changing the chain-like storage structure into a DAG of blocks was NXT. If the time of mining remains unchanged, the storage could be extended by X times with X blocks on the network at the same time. Qitmeer is the first public chain that is dedicated to serving the ecosystem of ethics finance, socially responsible investment and Islamic Finance, which aims to act as the overall financial infrastructure to seamlessly converge all these areas, thereby enhancing financial inclusion. Cutting Edge Public Chain Based on BlockDAG – Qitmeer stands for the state of the art of distributed ledger technology up to present, which adopts an open and technology that is rooted in the typical chain data structure of Bitcoin. Qitmeer adheres to classic POW(Proof -of-Work) based on the BlockDAG(Directed-Acyclic-Graph) consensus protocol, which aims to achieve the desirable balance among security, openness, fairness and scalability. Qitmeer developed a unique OP_TOKEN asset issuance mechanism model based on the UTXO (Unspent Transaction Output), which is secure and efficient to support the tokenization of large volume transaction-level liquid it and its frequent secondary market trading activities.