A junction box (100) includes a cable connecting box, a cover (2) covering the cable connecting box, and a cable (4) connecting with the cable connecting box. The cable (4) connecting box has an insulative block (5), a number of contacting foils (6), and a number of diodes (31) connecting adjacent contacting foils (6). The junction box (100) further includes a plurality of clips (9) mounted in the insulative block (5) and electrically connecting with the contacting foils (6). The clip (9) includes a clamp spring (91) and an elastic plate (92) received in the clamp spring (91) to resist the clamping spring (91). As a result, the clamp spring (91) will not resist the cable connecting box so as to improve an using life of the junction box (100).