The purpose of this study is to evaluate and compare safety and effectiveness of Chemotherapy in Combination With Erlotinib,or Sequential Erlotinib for Treatment in Patients With EGFR - TKI Resistance of EGFR Mutations

from the first cycle of treatment (day one) to two month after the last cycle

Inclusion Criteria:

1. Sign the informed consent
2. ≥18 years
3. According to RECIST 1.1 standard, at least one measurable lesions
4. Histology and cytology confirmed with unfavorable surgical locally advanced stage (stage IIIB) or metastatic NSCLC (IV), Sensitive EGFR gene mutation
5. Palliative treatment has received two medicine first-line platinum-based chemotherapy and EGFR - TKI second-line treatment and objective clinical benefit (CR, PR or SD is more than 6 months), RESIST standard curative effect evaluation for progress
6. PS=0,1,2
7. No serious blood, heart, lung, liver and kidney dysfunction, and immune deficiency
8. Hb≥9g/dL；WBC≥3*109/L，ANC≥1.5*109/L，PLT≥75*109/L
9. Men or women of childbearing age in the experiment are willing to take contraceptive measures
10. Estimated survival period for 3 months or more

Exclusion Criteria:

1. The palliative chemotherapy ever use docetaxel and pemetrexed
2. small cell lung cancer non small cell hybrid
3. Women during pregnancy or lactation
4. In the past the anti-tumor treatment of any outstanding ease of > CTCAE 2 levels of toxicity
5. Ccr<30 ml/min (calculated by Cockcroft-Gault formula)
6. hepatic insufficiency： Tbil> 1.5×ULN ALT and AST > 2.5×ULN (Patients with liver metastasis>5×ULN) Alkaline phosphatase>2.5 ×ULN(Patients with liver metastasis>5×ULN)
7. Severe symptomatic heart disease
8. Symptomatic brain metastases
9. In the last 5 years have been or are suffering from other histological types of malignant tumor
10. There are serious or uncontrolled systemic diseases
11. During the study period planned radiotherapy on target lesion
12. During the study period, plans to use other antineoplastic therapy
13. Clinical study on treatment of 30 days beginning period prior to participate in any study drug