The dissertation studies the architecture of broadbandintelligent network (BIN) and implementation of video conference based on ATM network and of multicast routing problem on video conference using BIN under the aid of the important task-Study of IN and B-ISDN Integration (69896244)-sponsored by National Natural Science Fund. A lot of points of view and solutions are present. The main contributions in the dissertation are as follows: (1) Design the new architecture of BIN and improve the architecture of BIN proposed by ITU-T. It is easy to set up the connections of video conference using the new architecture of BIN.(2) Present the detailed scheme that BIN controls and implements video conference without specialized resource function, study the scheme of all the media on video conference transmitted and switched under the control of BIN, and discuss how to implement point-to-multipoint communications using BIN. (3) First present the scheme of implementing multicast routing algorithms on video conference using BIN.(4) Explicitly introduce a series of concepts including neighboring node, neighboring node set, neighboring edge, then propose an Adjustable Dynamic Multicast (ADM) routing algorithm which is suitable for video conference, analyze its performances, and prove the algorithm is appropriate and feasible. (5) Develop a degree-constrained dynamic multicast (DADM) routing algorithm which can find less cost multicast routing tree. The results of simulation and experiments confirm that DADM algorithm can find the less cost multicast tree. Finally, analyze the relation between the size of degree-constrained and value of multicast tree cost. (6) Present a delay-constrained dynamic multicast routing algorithm suitable for video conference characteristic, and advise a series of schemes reducing the delay of transmitting all the media on videoconference.(7) First propose implementing the reliable multicast routing transport protocol using BIN, thereby ACK implosion problem can be solved. The protocol only requires finite memory and is scalable.