We present the design and basic performance of the MTCA.4-based electronics developed for the new LLRF and BPM systems in SPring-8, which are substitutes for electronics more than 20 years old. We have developed MTCA.4 modules for the new systems, such as a high-speed digitizer AMC, an LLRF RTM, a BPM RTM, and a clock and RF distribution eRTM. To reduce the number of cables, we employed an RF backplane to distribute the clock and the reference RF signals. The high-speed digitizer AMC has 10 ADC channels and 2 DAC channels having a sampling rate of 370 MSPS maximum and a vertical resolution of 16 bits. Input signals with the frequency of 509 MHz are detected in an under-sampling scheme. The digitizer AMC is common to both LLRF and BPM electronics, but the FPGA firmware is different. The input signals are processed by RTMs and transferred to the digitizer AMC. The LLRF RTM has 9 ch. RF inputs, 1 DC coupling input, and 1 vector modulator output. The BPM RTM has 8 signal inputs, corresponding to 2 BPMs. Both RTMs can pass through the ADC sampling clock and the reference signal to the digitizer AMC. The signals for the RF backplane are generated by a newly developed eRTM. We finished the replacement from the old LLRF electronics to the MTCA.4 system last year and now testing BPM electronics with an actual electron beam. Both LLRF and BPM systems are working well in the SPring-8 storage ring.