It is worthy of research to do the analogue circuit design using Operational Transconductance Amplifiers (OTAs) and Capacitors (Cs) because an OTA is equivalent to both an active element and a resistor leading to a more condensed integrated circuit without resistors ,and because the equivalent resistor value can be electronically tuned varying the bias current. Due to the difficulty to precisely fabricate the capacitance in integrated circuits, it becomes an important research work to find a tunable element for the replacement of the capacitor used to realize the s terms in transfer functions. The input-and-output relationship of an Operational Amplifier (OA) is shown as below.in which is the gain, the bandwidth , and the product of both gain and bandwidth . It is exhibited that, an OA can also be used to realize the s terms in transfer functions. Hence, is the variable . In this thesis , we have found that the is variable tuning either the bias current or the inner compensation Capacitance of an OA just like the variation of the trancondance of an OTA through the tuning of its bias current. Therefore, the capacitor with error fabricated in the integrated circuits can be replaced by the OA tunable through its inner bias current. In the thesis, we proposed the Structures using Adjustable Active elements and a Single Grounded Capacitor.In is not change any circuit situation of structure to need, can realize Low-pass、High-pass and Band-pass Filter Structures, three kinds filters.General OTA-C two stepses of circuit are all two electric capacities at least, in the thesis a condenser among them changes into having adjustable OA, and this adjustable OA can solve the problem that the electric capacity is unable to make perfectly .It is worthy of research to do the analogue circuit design using Operational Transconductance Amplifiers (OTAs) and Capacitors (Cs) because an OTA is equivalent to both an active element and a resistor leading to a more condensed integrated circuit without resistors ,and because the equivalent resistor value can be electronically tuned varying the bias current. In order to make the circuit have very good accuracy, so according to Butterworth rule, and prove with the actual simulation result in order to reach the result with the mathematical measurement type of the susceptibility. Do real verification to this circuit put forward of thesis. Utilize Hspice carry on circuit characteristic simulation in imitating , use tsmc035 parameter make verification of simulation Cheng to go on to come, utilize the ideal result that Matlab receives to strain wave performance (Filtering performance), the relevant characteristic compare with proving not probing into and not noting down by way and data as after study by reference material of effect not ideal non-.