Conformance test is performed to verify and validate the correctness of a system implementa- tion.In view of easily causing the problem of state space explosion

and due to time constraint in data processing for real-time system

a symbolic test generation method is proposed.Firstly

symbolic transition systems and timed automata are extended to establish a semantic model TSIOSTS

based on which an extension of timed conformance relation tioco is defined.Then

with tioco and the symbolic execution strategy

a symbolic timed behavior tree of the system model under test is yielded and transformed into test cases.Finally

the proposed method is applied to conformance test of temporary speed restriction server of the CTCS-3 train control system

and the results present feasibility and validity of the method.